It took Debbie 3.6 hours to drive to her mother's house on Thursday morning. On her return trip on Friday night, traffic was heavier, so it took her 4 hours. Her average speed on Friday was 4 mi/hr slower than on Thursday. What was her speed on Friday?

Question

Natalya Woods

Mathematics

27 December, 09:21

It took Debbie 3.6 hours to drive to her mother's house on Thursday morning. On her return trip on Friday night, traffic was heavier, so it took her 4 hours. Her average speed on Friday was 4 mi/hr slower than on Thursday. What was her speed on Friday?

+4

Answers (1)

Know the Answer?

Jaydin Marsh · Answer 1

36 mph

Step-by-step explanation:

d = rt

d = (x) (3.6)

d = (x-4) (4)

3.6x = 4x - 16

-0.4x = - 16

x = 40

Her speed was 40 on Thursday, so 36 on Friday