Question

A man had to walk a certain distance. He covered two thirds of
it at 4kmph and the remaining at 5 kmph. If the total time taken is
42 minutes, find the total distance.
et th
the
​

Answer 1

Let the distance be 'x' km.

Therefore total time taken =

$\frac{2x}{12} + \frac{x}{15} hours$

$⇒( \frac{2x}{12} + \frac{x}{15} )hr = 42 \: \: mins$

$⇒( \frac{2x}{12} + \frac{x}{15}) hrs= \frac{42}{60} hrs$

$\frac{2x}{12} + \frac{x}{15} = \frac{42}{60}$

$\frac{10x+4x}{60} = \frac{42}{60}$

$⇒ 14x=42$

$⇒x=3$

Total distance x=3km