SOLUTION: It took 4.5 hours to drive to her mother's house. On her trip on Sunday , it took 5 hours. Her average speed on Sunday was 4mph slower than on Saturday. What was her average spe

Question 266541: It took 4.5 hours to drive to her mother's house. On her trip on Sunday , it took 5 hours. Her average speed on Sunday was 4mph slower than on Saturday. What was her average speed on Sunday?
Answer by drk(1908) (Show Source): You can put this solution on YOUR website!
This is an RTD problem. Here is a table based on the above information:
driving . . . . rate . . . . time . . . . distance
Sat . . . . . . . . r . . . . . .(4.5) . . . . . . 4.5r
Sun . . . . . . . r - 4 . . . . 5 . . . . . . . . 5r - 20
total . . . . . . . . . . . . . . .9.5 . . . . . . 9.5r - 20
-----
Looking at the third column, we get
4.5r = 5r - 20
subtract 5r to get
-.5r = -20
r= 40
-----
her average speed Saturday was 40
her average speed Sunday was 36
RELATED QUESTIONS
It took Gina 1.8 hours to drive to her mother's house on Saturday morning. On her... (answered by josgarithmetic)

It took Fran 5.4 to drive to her mothers house on saturday morning. On sunday it took her (answered by lwsshak3)

It took Cathy 1.81 hours to drive to her mother's house on Sunday morning. On her... (answered by josgarithmetic)

It took Cathy 1.81 hours to drive to her mother's house on Sunday morning. On her... (answered by ankor@dixie-net.com)

it took Betty 4.5 hours to drive to her mother's house on monday morning. on her return... (answered by stanbon)

It took Gina 3.6 hours to drive to her mother's house on thursday morning.On her return... (answered by josgarithmetic)

It took Debbie 5.4 hours to drive hours to her mothers house on Wednesday morning. On her (answered by Alan3354,Boreal)

Char travels 3.6 hours on Saturday to visit. On Sunday she travels the same distance in (answered by mananth)

It took Debbie 5.4 hours to drive to her mother's house on Thursday. On her returning... (answered by checkley79)