Brian drove 120 miles at a speed of 60 mph. He drove the same distance back home at an average speed of 40 mph. Brian adds the s

Question

3 years ago

13

Brian drove 120 miles at a speed of 60 mph. He drove the same distance back home at an average speed of 40 mph. Brian adds the s

peeds and divides by two to come up with an average speed of 50 mph what is wrong with his reasoning? Find his average speed

Mathematics

1 answer:

Helen [10] · Answer 1 · 2022-02-19T21:56:43+03:00

Helen [10]3 years ago

4 0

This is how to find the average speed: the total distance ÷ the total number of hours
the total distance in this case is 120+120=240
the total hours is 120/60 + 120/40 =2+3=5
so 240/5=48
48 miles per hour