SOLUTION: Fred can mow a lawn in 120 minutes. Rocky can mow the same lawn in 80 minutes. How long does it take for both Fred and Rocky to mow the lawn if they are working together?

Algebra.Com
Question 1018913: Fred can mow a lawn in 120 minutes. Rocky can mow the same lawn in 80 minutes. How long does it take for both Fred and Rocky to mow the lawn if they are working together?
Answer by josmiceli(19441)   (Show Source): You can put this solution on YOUR website!
Let = their time in minutes working together
Add their rates of working to get their rate working together
Fred's rate:
[ 1 lawn ] / [ 120 min ]
Rocky's rate:
[ 1 lawn ] / [ 80 min ]
Rate working together:
[ 1 lawn ] / [ t min ]
--------------------

Multiply both sides by



-------------
It takes them 48 min to mow
lawn working together
--------------------
check:






OK

RELATED QUESTIONS

Betty can mow a lawn in 40 minutes. Melissa can mow the same lawn in 20 minutes. How long (answered by Edwin McCravy)
Sam can mow a lawn in 30 minutes. Melissa can mow the same lawn in 90 minutes. How long... (answered by Boreal,greenestamps,Alan3354)
siam can mow a lawn in 60 minutes. larry can mow the same lawn in 30 minutes . How long (answered by josmiceli,Alan3354)
Sam can mow a lawn in 80 minutes. Bullwinkle can mow the same lawn in 120 minutes. How... (answered by ankor@dixie-net.com,Alan3354)
Bob can mow the lawn in 5 hours, and Fred can mow the lawn in 4 hours. How long will it... (answered by josgarithmetic)
John and Fred must mow the lawn before they can go swimming. By themselves, John would... (answered by ankor@dixie-net.com)
Peter can mow a lawn in 40 minutes. John can mow the same lawn in 60 minutes. How long... (answered by ikleyn,josgarithmetic,math_tutor2020,greenestamps)
Fred can mow the lawn in 1 hour. John can mow the lawn in 2 hours. How long will it take... (answered by stanbon)
Mowing a lawn. Adam can mow a lawn in 40 minutes, while his cousin Victor can mow the... (answered by richwmiller)