A car moves at 40 km/h for 30 minutes and then at 60 km/h for 45 minutes. What is its average speed for the trip?

Explanation

1. 01

   Distances: $40 \times \frac{1}{2} = 20$ km and $60 \times \frac{3}{4} = 45$ km.

2. 02

   Total 65 km in $\frac{5}{4}$ h.

3. 03

   Average speed $= 65 \div \frac{5}{4} = 52$ km/h.