Question

A journey by bus takes 45 minutes at 40 km/h, How fast must a car go to undertake the same journey in 25 minutes.

Answer 1

Distance covered by bus in 45 minutes with speed of 40 km/h = $40\times \frac{45}{60}$ $[\because speed=\frac{Distance}{Time}]$

= 30 km.

speed that can be to covers the same journey in 25 minutes = $\frac{30}{\frac{25}{60}}=\frac{30\times 60}{25}km/h$

= 72 km/h.