Question

A bus travelling at $42km/h$ covers a distance in $5hours$. How much time would it save if it increased its speed by $8km/h$.

Answer 1

Given : Original Speed $=42km/h$, and Original time, t $=5hours$

Distance $=$ speed $\times$ Time $=42\times 5=210$ km

If the speed is increased by $8km/h$ then, the new time will be

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

$=\frac{Distance}{Originalspeed+8}[\because \text{Distance is same}]$

$=\frac{210}{(8+42)}$

$=\frac{210}{50}$

$=4.2hours$

He would save time $=5-4.2=0.8hours$ .