Aptitude - Time and Distance - Discussion

3. 

If a person walks at 14 km/hr instead of 10 km/hr, he would have walked 20 km more. The actual distance travelled by him is:

[A]. 50 km
[B]. 56 km
[C]. 70 km
[D]. 80 km

Answer: Option A

Explanation:

Let the actual distance travelled be x km.

Then, x = x + 20
10 14

14x = 10x + 200

4x = 200

x = 50 km.


Raghavendra said: (Aug 4, 2010)  
I'm not clear with the answer. Why did you take the time same in both the cases?

Gowtham said: (Aug 25, 2010)  
For the same interval if the person travelled in 14 kmph so only.

or else you could solve like this

1st hour 10 =14
2nd hour 20 =28
3rd hour 30 =42
4th hour 40 =56
5th hour 50 =70

At speed 10 kmph he reaches 50 km at the same time if he travels in 14 kmph he would reach 70 km. So 70 - 50 = 20. I think u got it.

Satish said: (Aug 31, 2010)  
Please give express that how to make this equation ?

Nitesh said: (Oct 9, 2010)  
@Gowtham

But it is not written that time instance is same.

Savitha said: (Oct 18, 2010)  
I am not clear with the explanation and I didn't understand this step x/10=x+20/14.

Kinnari said: (Oct 19, 2010)  
It goes by the formula S=D/T (Speed = Distance/Time)

So, T = D/S => T=x/10 ............(1)

T = x+20/14 .........(2)

Taking both the times together we get frm (1) and (2)

x/10=x+20/14

Now solve it as shown above. Hope you get it now.

Krishna said: (Dec 17, 2010)  
I agree with gautam .... the time is not constant in both cases.
So it is false ..... how to equate them


He travels at 10km/hr and walks d km in t1 hrs

Similarly, he travels at 14km/hr and walks (d+20)km in t2 hrs

How can u equate t1 and t2? It is not given.

Ankit said: (Dec 23, 2010)  
Thanks kinnari. I got it.

Muneer said: (Dec 24, 2010)  
Let distance travelled be x,

Since the time taken is same here so,

time taken to walk 14 km more at speed 14 kmph =time taken to walk the distance at speed 10 kmph

(x+20)/14=x/10

5x+100=7x

2x=100

x=50

Xyz said: (Dec 31, 2010)  
Why did you take time same in both the cases?

Santosh said: (Feb 13, 2011)  
I got you Gowtham you expressed very clearly thnks 4 your expalnation.

Ilesh said: (May 22, 2011)  
Just think more here extra 4km/h speed made him to cover extra 20km right,
den

4km/h is........20km(it clearly tells 1km/h is..5km)
10km/h is.......?(10*5=50km)

Gowthami said: (Jun 7, 2011)  
Thanx illesh. I got it.

Kiran said: (Jun 17, 2011)  
Time = Distance / Speed
Let Distance = x
First Case : Person's usual speed is 10km/hr
So, T = D/S and putting the values in formula we get : T = x/10

Second case : if he travels at the speed of 14km/hr then he would have walked 20 km more.

We have already assumed distance as x and now in second case we have 20 km more So:
T=D/S, x+20/14

So, we have:
x/10 = x+20/14
And solving the above ,we get
14x = 10x+200
14x - 10x = 200
4x = 200
x = 50Km

Krishna Reddy.Gongati said: (Jul 7, 2011)  
I am not clear with the explanation and I didn't understand this step x/10=x+20/14.

Anu said: (Aug 12, 2011)  
How we get the 200 here? In this answer please help me in this case.

Selvam said: (Aug 29, 2011)  
Hey anu see cross multiplication

So,
x/10=(x+20)/14
first multiply the (x+20) by 10 and u ill get 10x+200
second multiply the x by 14 so u ill get 14x
now 14x=10x+200
14x-10x=200
4x=200
x=200/4
x=50

I hope you will understand this.

Harpreet Kaur said: (Sep 14, 2011)  
I liked the explanation given by Kinnari. I thank you for that.

Arti said: (Sep 24, 2011)  
Thanks to ilesh I got it.

Lak Verma said: (Oct 10, 2011)  
Time not given in question so let it (X) then
Speed*time=distance
14x -10x=20
X=5 hr
So 10*5=50km question asking for distance

Rahul said: (Oct 18, 2011)  
The question is asked to find out the distance traveled by the person, and its clearly written he traveled 20km more so we equate it as (x+20) as the distance traveled by him and then when we get the value of X to be 50km. Why it is not added by 20km to get final answer as 70km ?

Jayaraj said: (Nov 24, 2011)  
Kinnari's explanation is simple and good.

Thirumoorthy Lalapet Karur(Dt) said: (Dec 30, 2011)  
Note: That in both speed Time will be same so

for speed 10km/hr speed=distance/time
10 =x/time1
for speed 14km/hr 14 =(x+20)/time2

: Note time will be same so we equate these two equations respect with time

time1 = time2
time1 = x/10
time2 = (x+20)/14
(X/10)=(X+20)/14
we solve this to obation right answer

Manoj said: (Feb 1, 2012)  
@Ilesh method is best one.

Shro said: (Feb 17, 2012)  
The persons speed of walking is 14km/hr.
He should have walked 10km/hr.
If he had gone with the speed of 10km/hr then he would have walked more den 20km/hr.
So,We are supposed to imagine if he had walked 10km/hr speed then what would be his actual speed.
So,we assume that let the distance be X km.


Then, the formula comes into picture i.e. speed=distance/time

So , as we are supposed to find as per the expectation if he had walked 10km/hr :
we take 10km/hr as his walking speed.
Distance is we are supposed to find more than 20
i.e. 20+X.
time is what the person actually doing .In reality the person is walking at 14km/hr.

So,in short with respect to person's capacity i.e. 14km/hr we can find the exact answer.
and therefore

Another formula for 10km/hr is :
time =distance by speed
i.e. time=X/10

time= X / 10 becomes the 1st equation....
time= (X + 20 ) / 14 becomes second equation....
from the above 2 eqns :
(X / 10 ) = (( X + 20 ) / 14)
then solve the further equation ....
Hope u got it :)

Ravi said: (May 30, 2012)  
As time is same in both the case. Therefore distance is directly proportional to speed. Let distance is x.

x directly proportional to 10km/hr.
So, x/10 directly proportional to 1 km/hr.
And (x/10) *14 directly proportional to 14 km/hr.
And (x/10) *14 is the total distance covered in 2nd case which x+20.
So just compare both the distance i.e.
(x/10) *14 = x+20. You will get x=50. Answer.

Mmk91 said: (Jun 4, 2012)  
still confusion guys

Nandhu said: (Jun 6, 2012)  
How you getting this (x+20) /14.

Raji said: (Jul 11, 2012)  
Ilesh method is good procedure than others because in question there is no clarity that the time is same.

Anand said: (Jul 22, 2012)  
Ilesh logical thinking sweet and simlpe...

Tanay said: (Aug 14, 2012)  
In 4 kmph he walk more 20 km.

So in 1 kmph he walks (20/4) =5 km.

Thus in 10 kmph he walks (5*10) =50 km (actual distance).

Laxman said: (Aug 22, 2013)  
The actual distance should be the 10hr/km i.e. (50km ) + extra 20KM = 70 km?

Anjith said: (Aug 24, 2013)  
Hi,

The man travels at a speed of 14, but he assumed to travel at a speed of 10 kmph.

Means the man covered 70km, but he assumed to cover is 50 km.

Hence the actual distance covered by the man is 70 kms, and it is the answer.

Please let me know if I am wrong.

Sohail said: (Sep 5, 2013)  
We can do this in simple unitary method; like,

If the man travels at the speed of 14 km/hr he covers 20 extra km than if he travels at 10 km/hr.

Therefore we can see this extra 4 km/hr speed helps him to cover 20 km.
Now we can write in:

4 km/hr speed he covers 20 km;

1 km/hr speed he cover 20/4 km;

Now in (original speed) 10 km/hr speed he covers 20/4 x 10 = 50 km.

Gaurav Ralhan said: (Oct 2, 2013)  
But it is not written that time instance is same.

Bhat said: (Oct 11, 2013)  
Difference between distance i.e. 14-10 = 4.

Now calculate avg distance i.e. 20/4 = 5.

Now actual distance = 10*f = 50.

Keerthi said: (Dec 25, 2013)  
First the question is find actual distance.

Then given: speed 14 kmph and 10 kmph .

T=D/S.
Actual distance is considered:x.
T=x/10,x+20/14.
x/10=x+20/14.

Then simplify the equation answer is 50.

Jeeva said: (Jul 9, 2014)  
Extra 4kmhr------20km more.
So 1kmhr------ ?

20*1/4 so = 5.

so 10km*5 = 50.

Santoshganur1@Gmail.Com said: (Jul 13, 2014)  
Actual distance = xkm.

Simply a person walks 14 km instead 10 km,

So 14-10 = 4.

10*20 = 200.
200/4 = 50;

Kiran said: (Jul 13, 2014)  
If this person walks 10km then he walks xkm.
If this person walks 14 km then he will be walks x + 20 km.

Then 10 kmph -> x km.
&14 kmph -> x + 20 km.

So 10 * (x + 20) = 14 * x.

10x + 200 = 14x.

4x = 200.

x = 50 km.

Bill said: (Jul 27, 2014)  
14-10 = 4km/hr more at 14, 20km/hr extra distance.
20/4 = 5hrs.

5*14 = 70 is the answer.

Siva Nandi Reddy said: (Sep 4, 2014)  
The difference between the two speeds is 20 km in the above question.

4km/h----------20km.
So 10km/h---------?

Cross multiplication so we get 50 km/h.

Sunil said: (Sep 24, 2014)  
Time in this solution is 1 hr since it is km per hour and then x/10 would be for 1 hr and x+20/14 would also be for 1 hr.

Hence they can be equated. So this in other words is a unitary method.

Reality Check said: (Oct 1, 2014)  
Walking at 14 km/h or even 10 km/h is. Unrealistic.

Raj Arj said: (Oct 16, 2014)  
10km/hr-------------->x km.
14km/hr-------------->x+20 km.

So cross multiplication,
10(x+20) = 14x.
10x+200 =14x.
200 = 14x-10x.
200 = 4x.
x = 50 km.

Sahil said: (Oct 20, 2014)  
Speed 40% of x = 20.

Solving x =50.

Santoooosh said: (Dec 5, 2014)  
It is very clear. The time in both the cases is same that is 5 hrs.

T = 5;

Now the distance travelled by him at a speed of 10 kmph is x/10 in 5 hrs.

Similarly the distance travelled by him at a speed of 14 kmph is (x+20)/14 in 5 hrs.

Form that we can say that x/10 = 5, and (x+20)/14 = 5;
From the above x/10 = (x+20)/14.

Solve this you will get the answer.

Vijay said: (Jan 11, 2015)  
5*10 = 50 because t = 5 and Distance = Speed*Time.

Suman said: (Jan 18, 2015)  
14x-10x = 20.
4x = 20.
x = 5.

Actual distance = 10*5 = 50.

Mallikarjun said: (Feb 24, 2015)  
Difference of speed 14-10 = 4.

Therefore 4 km ----> 20.

So 10 km to travels 50 km.

Ketan said: (Mar 22, 2015)  
Here time is never given.

So consider man named.

Ashok walk with speed 10 km/hr, he travel for next 2 hour so distance he cover is 20 km.

2nd person named.

Madhu walk with speed 14 km/hr, he also travel for 2 hour so distance he cover is 28 km.

Now Madhu travel more 20 km wit speed 14 km/hr. So we subtract that 20 km from distance he travel in 2 hour.

= 28-20 = 8 km.

It means if we consider time 2 hour. Which is not given, so the answer will be 8 km?

Is it true?

Manish Nair said: (Apr 16, 2015)  
It came by this formula S = D/T (Speed = Distance/Time).

Here we take this formula such as:

T = D/S.

Let consider actual distance x km.

T = x/10.....(1).
T = x+20/14.....(2).

Taking both the times together we get from (1) and (2).

x/10 = x+20/14.
14x = 10x+200.

4x = 200.
x = 50km.

Hope you get it now.

Guna said: (May 6, 2015)  
I can't understand please explain clearly.

Tarun said: (May 9, 2015)  
Actual distance traveled be X km.

X/10 = X+20/14.

X = 50 kmph.

Sukumar Satyen said: (May 18, 2015)  
Let time taken to go certain distance = t hours.

At speed of 10kmph, distance covered = 10t kms.

At speed of 14kmph, distance covered = 14t kms.

Because, 10t < 14t.

Therefore, 10t + 20 kms = 14t.

=> 14t - 10t = 20 kms.
=> 4t = 20 kms.
=> t = 5 hours.

Now, his actual speed is 10kmph.

Therefore, actual distance covered = 10t = 50kms.

Krish said: (Aug 6, 2015)  
Guys if two boys are given a constant time (10min). One boy who walks little slower covered small distance 500m only at 10min. Another boy who walks faster covers more distance 800m at that constant time (10min). If time is kept constant means only distance covered varies.

Likewise If a constant distance given means time taken by two boys to reach that distance varies.

Mayur said: (Sep 10, 2015)  
Can you provide proper steps of answer? I'm not getting it.

Niel said: (Sep 18, 2015)  
See if the person generally walk at the speed of 10 km/hr but he walk 14 km/hr and by this speed he walk 20 km more. Means from this extra 4 km speed he covers the extra distance of extra 20 km in 5 hours.

So if he walk 5 hour at the speed of 10 km/hr the distance cover is 50 km and with the speed of 14 km/hr he covers 70 km. But he is a man and he has its stamina also means more speed less time of walking because he tired at the same point of his body capacity in both speed.

So if he will a machine then the answer is 70 km but he is a man and hence we have to deduce the extra 20 km and the answer is 50 km.

Kunal said: (Oct 22, 2015)  
First calculate as:

Time = Distance/Speed = 20 km/14-10 kmph = 20/4 = 5 hr.

Means time = 5 hr.

Distance = Time*Actual speed.

Distance = 5*10 = 50 km.

Krups said: (Oct 30, 2015)  
I think answer here should be 70 km as, here actual distance travelled is asked for which speed is 14 km/hr.

Let actual distance travelled is x, then.

x/14 = x-20/10.

Gives x = 70.

Salman said: (Nov 13, 2015)  
So much complicated answers who said time is not given.

The man travels with different speeds but for the same time.

Let's assume that time as x.

Now for the same time, the distance travelled is different because speed is different.

Now Distance = Speed*Time.

For the same time, distance travelled will be greater for higher speed i.e. 14 kmph and the difference of distance is 20 km.

So 14x-10x = 20 (since 20 km more). x = 5 i.e. Time = 5 hrs.

So actual distance is 10*x = 10*5 = 50 kmph.

The answer comes in two steps I explained to make it easier.

Monika said: (Nov 30, 2015)  
Can you please explain me the question in detail?

Sushil said: (Jan 11, 2016)  
What is the meaning of actual here? Either 14 km/hr or 10 km/hr.

Bishal Gupta said: (Jan 18, 2016)  
Easy way:

Actually travelled 10 kmph.

If travelled 14 kmph then he would have travelled 20 kmph more.

14-10 = 4.

Means 20/4 = 5.

Then actually he travelled 10 kmph.

So, 10*5 = 50 answer.

Hemanth said: (Jan 25, 2016)  
Here in this question both the times are equal. So we use s1/d1 = s2/d2.

Therefore: 10/x = 14/x+20.

10x+200 = 14x.

4x = 200.

x = 50.

Sonia said: (Mar 23, 2016)  
Time is considered as equal in both cases because of its average speed. Look over the question again. Speed is 14kmph & 10 kmph. It means 14 km travelled in one hour and 10 km travelled in one hour. So the time in both cases is the same.

Bdboy Hasan said: (May 2, 2016)  
Speed increase 14 - 10 = 4 kmph and so that distance increase 20 km.
When distance increases 4 km then time is 1 hour.
When distance increases 1 km then time is 1/4 hour.
When distance increases 20 km then time is 20/4 hour or 5 hours.

So, he journeyed 5 hours in 10 kmph.
So, distance is 5 * 10 = 50 hour.

Note : This technique is more useful for quick calculation.

Kalinga Kumar said: (May 10, 2016)  
We know,

Time = Distance/Speed.

Let's take original distance is X.

Given,
Speed is 10km/1hr and 14km/1hr.

Now we can write,
1hr = X distance/10 speed --> (1).

Similarly,
1hr = (X + 20) distance/14 speed --> (2).

Now, put the value of (1) in (2).
We will get,

X/10 = (X + 20)/14.
14X = 10X + 200.
4X = 200.
X = 50.

Kavitha said: (Jun 28, 2016)  
@Manish Nair.

Thanks for your solution.

Gtg said: (Aug 1, 2016)  
I did not understand the concept.

Atiya said: (Aug 11, 2016)  
Thanks for all your hard work and solution.

Ziyauddin said: (Aug 16, 2016)  
@Gowtham.

Thanks, you expressed clearly.

Sidzwozz said: (Aug 23, 2016)  
@Ilesh.

Explained very well.

Raj said: (Sep 23, 2016)  
Here time is constant = t;

No old speed = 10 new speed 10*14/10.

D-14/10d = 20.

D = 20*10/4 = 50 km.

Feroz said: (Sep 29, 2016)  
14 - 10 = 4,
20/4 = 5,
5 * 10 = 50.

Jayant said: (Dec 12, 2016)  
@All.

Thanks, you all expressed clearly.

Krishna Sharma said: (Jan 4, 2017)  
Please solve this.

While covering a distance of 60 km, A takes 4 hours more than B. If A doubles its speed, A took 2 hours less than B. Find the walking speed using a simultaneous equation or quadratic equation.

Satya said: (Jan 24, 2017)  
Given;

14kmph at 20 km MORE i.e extra speed.
So we can write it as 4 kmph -20.,
Each km 20÷4 = 5.
Hence 10 * 5 = 50.

Vikash said: (Jan 26, 2017)  
Let actual distance x km.
Actual speed =10 kmph T1 = ?

Man walk 20 km more,
Distance = x + 20.
Speed = 14 kmph T2 = ?

Now T1 = T2.
D1/S1 = D2/S2.
x/10 = x + 20/14 after solving x (actual distance) = 50 km answer.

Sambath said: (Feb 3, 2017)  
@Gowtham, @Ilesh.

Both are explained very well. Thank you.

Sonia Choudhary said: (Feb 18, 2017)  
@Kiran.

Yes, I agree with your solution. Thanks for this solution.

Rajesh H said: (Mar 1, 2017)  
Detailed Explanation:

Cconsider,
Z is actual distance travelled (when going at 10km/hr).
X is time (Unknown).

Case: 1
travelling at normal speed (10Km/hr).
10Km-----------------@1 hr
ZKm-------------------@X hr

after cross multiplying each other we get;
10X=Z*1 means that 10X=Z---------1)

Case 2:
Travelling at 14Km/hr.
|||y
14Km-------------@1hr.
20+ZKm----------@Xhr.

here, 20+Z means 20Km + Z Km travelled by Normal Speed @ same X hour.

by cross multiplying we get,
14X=20+Z-----------------2)

just solve both equation 1) & 2.
sub 1 in 2
Z=10X ,we get 14X=20+10X.
so, 4X=20 , X=5 now, we are not questioned for hours but only we need distance so,sub X directly in equation 2).

We get 70=20+Z so Z = 70-20 = 50Km.

White said: (Mar 15, 2017)  
The actual distance 50km(10km) but he travelled 70km by 14kmph, the question is THE ACTUAL DISTANCE TRAVELLED BY HIM? Is it 70 or 50?

Hroshid said: (Apr 11, 2017)  
Suppose walking time of this man = t.
So the walking distance for 14kmph = 14 * t = 14t,
and the actual walking distance=10 * t = 10t.

So as question, we can say 14t-10t = 20km # 4t=20 #t=5.

So the actual distance travel by him = 10 * 5 = 50km.

Hope all of you understand.

Tejadeep said: (Jun 2, 2017)  
Why you take x+20 can anyone explain it? Please.

Nandu said: (Jun 11, 2017)  
S1 : S2 = d1 : d2 = 14 : 10,
Diff 4 parts 20,
1 part 5,

Initially at 10 speed = 10 * 5=50.

Dev said: (Jun 12, 2017)  
I am not getting this, please anyone help me.

Souvik said: (Jun 20, 2017)  
To take time as x is the easiest way to solve.

Anoop Krishna said: (Jul 16, 2017)  
Hey, friends.

This is the easiest way of thinking.

Let the distance travelled by walking at the speed of 10km/h be x.
Then the distance travelled by walking at the speed of 14km/h will be x+20(according to the question).
so, 14=x+20,
10=x.

Cross multiply and find the value of x.

Parikshit said: (Jul 22, 2017)  
If 10kmph will cover x distance than 14 will cover it faster. But why here 20 km is added to 14kmph distance. How can it be possible?

Surin said: (Jul 25, 2017)  
14:10
7:5

2 difference = 20,
So 20/2 = 10.
5*10 = 50 ans.

Mayur Jaiwal said: (Jul 28, 2017)  
14-10 = 4km,
10*20 = 200,
200%4 = 50.

Zainabfatima said: (Aug 15, 2017)  
Your explanation is very clear. Thank you so much @Ilesh.

Manish said: (Aug 20, 2017)  
But it can be 70 also as it is said actual distance traveled by him x+20 where x is 50+20=70.

Rachel said: (Aug 21, 2017)  
I agree @Ilesh.

Vignesh Strive said: (Sep 10, 2017)  
Thanks for easy explanation @Gowtham.

Manish Kumar said: (Sep 12, 2017)  
Hello friends.

The person walks 14kmph instead of 10 km that means his original speed is 10kmph.

By walking 4kmph extra speed he covers 20 km.

That means for 1kmph he will cover 5 km.

Then for 10kmph, he will go 50 km. It's so simple.

Sonu said: (Oct 10, 2017)  
Given data both are speed rate 1h. First take 1h =x/10, and second take 1h=x+20/14. Both are take time 1hour.

Chetan said: (Oct 12, 2017)  
Thank you @Ilesh.

Varun said: (Jan 24, 2018)  
I can't catch the concept, since he increased his speed from 10 to 14 so actual distance would have been 14*5=70.

Manish said: (Jan 28, 2018)  
If he travels xkm.

He would have travelled with the speed of 10km/hr. Thus time=>x10.
But he travels with 14km/hr and thus he travels extra 20km => x+20 km. Thus time=>x+20/14
Equating both,
X/10=x+20/14.

You will get 50.

Vishnu said: (Mar 22, 2018)  
Hi, friends.

Here both times are equal for traveling x, and x+20 so x/10 =x+20/14.

Manu M said: (Apr 6, 2018)  
@All.

The actual distance travelled is 70 Km instead of 50 km. If he travels in 10 Kph distance should be 50, but he walks at a speed of 14 kph. So the actual distance is 70 Kph. Please correct me if any corrections.

Krishna Sai Thota said: (May 2, 2018)  
He walks 14k/h instead 10k/h.
So he covered 20km in 20÷(14-10)= 5 hr.
So, D= 10* 5 = 50 Km.

Rakesh said: (Jun 20, 2018)  
Why did you take the same value in both cases? Please explain.

Reshma said: (Jul 9, 2018)  
I think the answer should be 70. Because the actual distance travld is 50+20=7.

Am I right?

Ani said: (Aug 3, 2018)  
Why not X/14= (x+20) /10?

Shivani K said: (Aug 9, 2018)  
The question says that if he travelled 14km/hr instead of 10km/hr he would cover 20km more so
(14 -10)= 4 km/hr.

Distance covered with speed of 4km/hr=20km.
1km/hr= 20/4,
= 5km.
Actual distance covered with 10km/hr.
10 * 5 =50 km.

Palani said: (Sep 3, 2018)  
Friends, we should first understand the concept.

The man walks at 10kmph covered certain distance X. Then man instead of walks at 14kmph covered certain distance X. So both are covering the distance x first. Then he will take an extra time to cover 20km.

The Time difference
D is=20km.

Formula=D = D[a/a-b].
=20(10/4)=50km.

Ramu Dhakal said: (Sep 14, 2018)  
Time = Distance/Speed.

For 10km/h,
T=D/S.
Let the actual distance be x.

Therefore T= x/10 -------> Eq 1
For 14km/h,
T=D/S
T= x+20/14 ------> Eq 2

By equation 1 and 2.
x/10=x+20/14,
x=50.

Pradyumnan said: (Sep 30, 2018)  
I am understanding now. Thanks All.

Jayesh said: (Oct 17, 2018)  
@All.

14-10 = 4km/hr.
4km/hr = 20km travelled.
so 1hr = 5km,
then 10km/hr = 10 * 5 = 50.

Dadi Ganesh said: (Oct 27, 2018)  
Well said, Good explanation. Thanks @Jayesh.

Ameer said: (Feb 15, 2019)  
@Jayesh.

You make it very easy to understand. Thanks.

Ameer said: (Mar 6, 2019)  
@All.

According to me;

1st hour 10 = 14,
2nd hour 20 = 28,
3rd hour 30 = 42,
4th hour 40 = 56,
5th hour 50 = 70,

IF IN ONE HOUR HE IS DOING 14, THEN IN THE FIFTH HOUR (14*5=60) TIMES UP.

At speed 10 kmph he reaches 50 km at the same time if he travels in 14 kmph he would reach 70 km.

So, 70 - 50 = 20. I think u got it.

OR
14-10 = 4km/hr.
4km/hr = 20km travelled.
so 1hr = 5km,
then 10km/hr = 10 * 5 = 50.

Sriram.G said: (Mar 26, 2019)  
Both are travelling at different speed but in the same amount of time.
So, if x is the distance travelled by A, then the time taken by A is x/10. then time = distance/speed.
And time taken by B is (x+20)/14.
Both A and B took same time so x/10=(x+20)/14.
By solving we get x=50.

Zayan said: (Mar 27, 2019)  
Why is there x/10?

Rayan said: (Jun 30, 2019)  
The another method.

Let's, time will be t.
so, 14t-10t=20,
or. 4t=20,
or, t=5.
so, the total distance is 5*0 = 50.

Arun said: (Jul 5, 2019)  
It's based on per hour that means time is constant. And when time is constant distance and speed will be directly proportional.

Speed : 14 : 10
=> 7:5.
Since distance is directly proportional.
Its ratio also will be 7:5
20 more means the difference of 7-5.

Sandeep Jayker said: (Jul 17, 2019)  
Distance= (a/x-y) * y.
a=20km
X=14 KMPH.
Y=10 KMPH.
(20KM/14KMPH-10KMPH) * 10KMPH.
(20KM/4KMPH) * 10KMPH.
So, the answer is 50KM.

Bimal Limbu said: (Sep 22, 2019)  
70 is the answer.

Sneha said: (Oct 10, 2019)  
You have found the result for actual distance (i.e. x) and they said at 14km/he would walk 20km more. So we should do x+20(i.e. 50+20) right? We get 70km.

Jinia Siga said: (Feb 27, 2020)  
I do not understand why x+20 has taken in solution?

Kamal said: (Mar 29, 2020)  
Present speed = 14 km/h & Regular speed =10 km/h.
Difference of speed =14- 10 km/h = 4 km/h.
That means;
If his speed more 4 km/h he completes 20 km.

If he runs at his usual he complete = 20/5) * 10 km = 50 km.

Amit said: (Mar 30, 2020)  
The correct answer should be 70 as the value of x is 50 at the speed of 10 km/hr but at the speed of 14 km hr is 20 more.

Sirisha said: (Apr 12, 2020)  
14x-10x=20,
4x=20,
X=5.
10*5=50km.

Mr.Dims said: (Apr 14, 2020)  
The Right answer is 70km.

Actually, he thinks that he needs to travel 10km/hr but he travelled 14km/hr.
In this case, he travelled extra 4km/hr, but finally, he travelled 20km extra.
So actual 50km+extra travelled 20km, total 70KM.

Vishnugpd said: (Apr 17, 2020)  
A:B
14:10
7:5.

Difference is 2parts.
2part=20km{actual difference).
1part=10km.
Multiply B part that is 5*10=50.

Sagar said: (May 8, 2020)  
Hi, whenever the time is constant we can equate the distance ratio to speed ratio. That is 10/14 =x/x+20 then x=50.

Anu said: (Aug 19, 2020)  
Thanks all for the explanation.

Ankit Singh said: (Sep 7, 2020)  
Take difference of 14 and 10 is 4.

4 km/hr speed decrease= 20 km more he go.
4unit = 20,
1unit = 5,
Then 10 * 5 = 50 km actual distance covered by him.

Md. Palash said: (Oct 12, 2020)  
The difference per hour is 14 - 10 = 4 km.
So, the time taken to travel 20 km is = 20/4 = 5 hours.
Now, the actual distance = 10 * 5 = 50 km.

Atul said: (Jan 7, 2021)  
Indirect proportion by chain rule.

X:X+20 10:14
Hence X/10 = X+20/14.
So, the answer x=50.

Parth Singh said: (Jan 8, 2021)  
Here time is constant.

S, the o formula for time is Distance /Speed.
10/x = 14/x+200.
Equate this we will find:
10x + 200 = 14x,
4x = 200,
X = 50.

Bhavesh Solanki said: (May 30, 2021)  
14km/hr - 10 km/hr = 4 km/hr(difference)
4km/hr - 20km,
10km/hr (?),
= 10*20/4.
= 50km.

Priya said: (Jul 6, 2021)  
He travels 4 km/hr extra in the other case.

So if he traveled 20 km more in that case then it means the time he took would be time= distance/speed = 20/4= 5 hours. So now that we know the time he took, we can find the actual distance he traveled.

Distance= speed* time= 10*5= 50 km.

Shreyoshi said: (Jul 19, 2021)  
Most people have the confusion that time is equal has not been stated equal in the question, Then, how can we equate the two entities based on the assuption that time is equal, right?


Let me explain;
if t=1st hour, distance=10...also, distance=14
t=2nd hour, distance=20...also distance=14+14=28
..
.
Similarly when t=5th hour, distance=50...distance=70
Now, the difference in respective distances =70-50=20
This means that the distance covered is 20 more in the 5th hour when speed is 14kmph instead of 10kmph.
This means, in the same time, the distance covered is different(i.e. 20km more->as stated in the question)
This proves that the time interval is the same irrespective of speed is different.
So, we equated the two statements since the time taken has to be the same. Hope you got it.

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