Question

A person walks from his house at a speed of 4 km/hr and reaches his school 5 min late. If his speed has been 5 km/hr , he would have reached 10 minutes earlier. the distance of the school from his house is

• A. 5 km
• B. 6km
• C. 7 km
• D. 8 km

Answer 1

The correct option is A 5 km

Let the actual time be 't'

and distance be x

Now according to first condition, we have

$\frac{x}{4}=t+\frac{5}{60}$

And according to Second condition, we have

$\frac{x}{5}=t-\frac{10}{60}$

$60x=4t+20$

$60x=5t-50$

Subtracting equation 1 from 2, we have

$0=t-70$

$\therefore t=70$

Putting the value of t we get $x=5km$