Myra cycles to a friend’s house 5 km away to deliver a packet. She goes at a…
2019
Myra cycles to a friend’s house 5 km away to deliver a packet. She goes at a speed of 12 km/hour and returns at a speed of 8 km/h. Her average speed during the whole trip is –
- A.
20 km/h
- B.
9.6 km/h
- C.
10 km/h
- D.
5 m/s
Attempted by 8 students.
Show answer & explanation
Correct answer: B
Average speed is total distance divided by total time. Myra travels 5 km to her friend’s house and 5 km back, so total distance = 10 km. Time taken = 5/12 + 5/8 = 10/24 + 15/24 = 25/24 hours. Average speed = 10 ÷ (25/24) = 9.6 km/h.