SOLUTION: If you travel from your home to the store for 12 minutes at 20 mph then you traveled back home along the same path downhill at 60 mph. What is the average speed to the store and ba

Question 942085: If you travel from your home to the store for 12 minutes at 20 mph then you traveled back home along the same path downhill at 60 mph. What is the average speed to the store and back?
Found 2 solutions by TimothyLamb, josmiceli:
Answer by TimothyLamb(4379) (Show Source): You can put this solution on YOUR website!
s = d/t
d = st
t = d/s
---
time from home to store (a):
a = 12 minutes * (1/60 hour/minutes)
a = 12/60 hours
---
distance from home to store:
d = st
d = 20t
t = a
d = 20*12/60
d = 4 miles
---
time from store to home (b):
t = d/s
b = 4/60 hours
---
total time:
a + b = 12/60 + 4/60
---
average speed for the round trip:
s = (2*4)/(a + b)
s = 8/(12/60 + 4/60)
s = 30 mph
---
Free algebra tutoring live chat:
https://sooeet.com/chat.php?gn=algebra
---
Solve and graph linear equations:
https://sooeet.com/math/linear-equation-solver.php
---
Solve quadratic equations with quadratic formula:
https://sooeet.com/math/quadratic-formula-solver.php
---
Solve systems of linear equations up to 6-equations 6-variables:
https://sooeet.com/math/system-of-linear-equations-solver.php
---
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
average speed is always:
( total distance ) / ( total time )

mi

----------------

hrs
-------------------
Ave speed =
Ave speed=
Ave speed =
Ave speed =
Average speed to the store and back is 30 mi/hr

RELATED QUESTIONS
Starting at home, Emily traveled uphill to the grocery store for 20 minutes at just 6... (answered by josmiceli)
Starting at home, Christopher traveled uphill to the grocery store for 30 minutes at just (answered by Alan3354)
Starting at home, Christopher traveled uphill to the hardware store for 50 minutes at... (answered by ankor@dixie-net.com)
Starting at home, Christopher traveled uphill to the grocery store for 90 minutes at just (answered by lwsshak3)
Starting at home, Stephanie traveled uphill to the gift store for 30 minutes at just 10... (answered by Alan3354)
Starting at home, Christopher traveled uphill to the hardware store for 24 minutes at... (answered by ankor@dixie-net.com)
Starting at home, Luis traveled uphill to the hardware store for 30 minutes at just 10... (answered by Alan3354)
Starting at home, Ishaan traveled uphill to the grocery store for 8 minutes at just 30... (answered by Alan3354)
Starting from home,James traveled uphill to the office supply store for 75 minutes for 4... (answered by stanbon,Alan3354,MathTherapy)