Question

A man with $\frac{3}{5}$ of his usual speed reaches the destination $2\frac{1}{2}$ hours late. Find his usual time to reach the destination?

Answer 1

Let the usual speed be x and time taken be y hours

speed $=\frac{Distance}{Time}$

$\Rightarrow$ Distance (D) = xy

Also,

$\left(\frac{3x}{5}\right)(y+\frac{5}{2})=$ Distance

$\frac{6xy+15x}{10}=xy$

$6xy+15x=10xy$

$4xy=15x$

$y=\frac{15}{4}$ hours

Usual time = $3\frac{3}{4}hours$