Question

A man can reach a certain place in $30$ hours. If he reduces his speed by $\frac{1}{15}$th, he goes $10$ km less in that time. Find his speed in km/ hr?

• A. $9$ km/hr
• B. $2$ km/hr
• C. $7$ km/hr
• D. $5$ km/hr

Answer 1

The correct option is D $5$ km/hr

Let the man's speed be $x$ km/hr.

Distance covered in $30$ hours = $30x$ km

New speed = $[x-\frac{x}{15}]km/hr=\frac{14x}{15}km/hr$

Distance covered in 30 hours = $\frac{14x}{15}\times 30=$ 28x km Given,$30x-28x=10km$ $\Rightarrow$ $x=5$km/hr