Question

A boy walks from his house to school at 2.5 kmph and arrives 12 minutes late The next day he walks at 4 kmph and reaches the school 15 minutes earlier What is the distance from his house to school?

• A. 2 km
• B. 2.5 km
• C. 3 km
• D. 3.5 km

Answer 1

The correct option is C 3 km

Let the distance of school and house is x k m

Then time taken at speed 2.5 km\hr=$\frac{x}{2.5}$ hr

And time taken at speed 4 km\hr=$\frac{x}{4}$ hr

$\therefore \frac{x}{2.5}-\frac{x}{4}=\frac{12}{60}\Rightarrow \frac{4x-2.5x}{10}=\frac{1}{5}\Rightarrow x=3$ km

Then the distance of school and house is 3 k m