Aptitude - Time and Distance - Discussion

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.

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 :)

@Ilesh method is best one.

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

Kinnari's explanation is simple and good.

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 ?

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

Thanks to ilesh I got it.

I liked the explanation given by Kinnari. I thank you for that.

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.