Aptitude - Time and Distance - Discussion

@Kiran.

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

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.

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?

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.

Why you take x+20 can anyone explain it? Please.

S1 : S2 = d1 : d2 = 14 : 10,
Diff 4 parts 20,
1 part 5,

Initially at 10 speed = 10 * 5=50.

I am not getting this, please anyone help me.

To take time as x is the easiest way to solve.

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.

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?