Question

A train has a speed of 60 km/h for the first one hour and 40 km/h for the next half hour. Its average speed in km/h is

• A. 50
• B. 53.33
• C. 48
• D. 70

Answer 1

Answer: (B)

53.33

Answer 2

Total distance travelled = $60 \times 1 + 40 \times \frac { 1 } { 2 } = 80 \mathrm {~km}$ and

Total time taken = $1 h r + \frac { 1 } { 2 } h r = \frac { 3 } { 2 } h r$

∴ Average speed $= \frac { 80 } { 3 / 2 } = 53.33$km/h