Question

Two men start together walk to certain destination one at 3 km per hour and one other at 3.75 km per hour. The latter arrive half an hour before the former find the destination

Answer 1

The answer is 15 kilometers.


SOLUTION :-


Let the destination be x km.

We know that :-

$distance = speed \times time \\ \\ time \: = \frac{distance}{speed}$
So,

Case 1:-

Speed = 3 km per hour
Distance = x km
So,
Time will be equal to :-
$time = \frac{x}{3} hours$

Case 2 :-

Speed = 3.75 km per hour
Distance = x km
So
Time will be equal to :-
$time = \frac{x}{3.75} hours$

Now,
In the question it is mention that the second man (in case 2) arrived the destination 1 hour before the first man (in case 1)
So,
Time taken by 1 - Time taken by 2 = 1

Putting the values :-

$\frac{x}{3} - \frac{x}{3.75} = 1 \\ \\ \frac{3.75x - 3x}{11.25} = 1 \\ \\ 0.75x = 1 \times 11.25 = 11.25 \\ \\ x = \frac{11.25}{0.75} \\ \\ x = 15 \: km$
Thus,
The destination is at a distance of 15 km from the starting point.