A person in a car drives along a straight road from point A to point B at a…
2020
A person in a car drives along a straight road from point A to point B at a speed of 60 km/hour for 15 minutes and then from point B to point C at a speed of 90 km/hour for 10 minutes. The average speed of his travel from point A to C is
- A.
75 km/hr
- B.
72 km/hr
- C.
68 km/hr
- D.
78 km/hr
Attempted by 8 students.
Show answer & explanation
Correct answer: B
Total distance: 60km/h * 0.25h + 90km/h * (1/6)h = 15 + 15 = 30km. Total time: 25 mins = 5/12 h. Avg speed: 30 / (5/12) = 72 km/hr.