A person drives 110 miles at 55 miles per hour, he drives the next 120 miles at 60 miles per hour, and then he drives the next 60 miles in an hour. What is his average speed for the entire journey in miles per hour?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 58.
Given that
A person drives 110 miles at 55 miles per hour,
he drives the next 120 miles at 60 miles per hour, and
he drives the next 60 miles in an hour.
Time = Distance/Speed
Average speed = Total distance/total time taken
Average speed = (110 + 120 + 60)/[(110/55)+ (120/60) + 1]
= 290/(2 + 2 + 1)
= 290/5 = 58 miles/h