A drives for 2 hours, 2.5 hours, 3 hours, 2 hours and 2.5 hours in five days of a week, respectively. His speeds on these days are 45 km/h, 50 km/h, 60 km/h, 70 km/h and 80 km/h, respectively. What is his average speed for the week?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 61.25 km/h.
Distance on Day 1 = 2 × 45 = 90 km
Distance on Day 2 = 2.5 × 50 = 125 km
Distance on Day 3 = 3 × 60 = 180 km
Distance on Day 4 = 2 × 70 = 140 km
Distance on Day 5 = 2.5 × 80 = 200 km
Total Distance = 90 + 125 + 180 + 140 + 200 = 735 km
Total Time = 2 + 2.5 + 3 + 2 + 2.5 = 12 hours
Average Speed = Total Distance / Total Time
⇒ Average Speed = 735 / 12
⇒ Average Speed = 61.25 km/h