Aptitude - Races and Games - Discussion

I am not getting it.

At last how the answers came as 20? please explain.

Does anyone know how can we solve this question by having the difference in distance values only( i.e, using 10 and 28)?

Please tell me.

Please anyone explain this in simple way.

@Ammu

I think throughout the race a, b&c have respective constant velocities.
That being said this problem can easily be solved using the concept of ratios.

Question is to find the distance btw b&c at the end of the race(when b reaches 100m).
It is given separation btw b & c when b reaches 90m is 18 (ie 90-72).
So, when b reaches 1m mark the Seperation btw them is simply 18÷90=1/5
When b reaches 100m ie end of the race the seperation is (1/5) * 100. =. 20.

I hope it is clear now.

Here, give indicates the distance that participants overtake each other.

So, A beats B by 10m in a 100m race indicates A finishes 100m whereas B finishes 10m behind A in the same time ie.) 90m.

Similiarly, A beats C by 28m indicates C covers 72m in the same time where A finishes 100m.
Now ratio of distance covered in a given time by B and C remains same ie.) 90:72 ie.) 5:4.

When, B covers 100m in a given time, C covers only 80 in the same time. So B beats C by a distance of 20m.

A finished 100m.
At that time.
B is 10m less than A, so B is 90.
C is 28m less than A, so C is 72.
The difference b/w in B and C is.
90-72 = 18.
When B is 90m then the difference is 18m.
When B is 1m the difference is 18/90=0.2m.
When B is 100m the difference is 0.2 * 100=20m.
At that time C will be 80m.
Ans is 20m.

@Raja.

Clear explanation. Thanks for that.

@All.

The solution is;

In same time A,B and C travel 100,90,72 meters respectively hence we can write:
100:VA = 90:VB = 72:VC where VA,VB,VC are velocities of A, B, C respectively.
Hence;
VB:VC = 90x:72x that means time taken by B to travel 100m is tb= 100/90x.
In this time C travel ( 100/90x)*72x = 80 m implies B gives C by 20m.

A gives B 10m means A beats B by 10m, A wins the race, by completing 100m, ie B will be at 10.

Thank you for the explanation @Akhil.