SOLUTION: Mark working alone can do 2 jobs in m hours, and Bob working alone can do 2 jobs in b hours. How long will it take Mark and Bob to do one job if they work together?

Question 1091243: Mark working alone can do 2 jobs in m hours, and Bob working alone can do 2 jobs in b hours. How long will it take Mark and Bob to do one job if they work together?
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
Mark's rate is
Bob's rate is
Add their individual rates to get
their rate working together
--------------------------------
Let = their time in hrs to do 1 job working together

Multiply both sides by

RELATED QUESTIONS
working together john and bob can paint a house in 3 1/2 hours. working alone bob can do... (answered by lwsshak3,macston)

If donald can perfrom a job working alone in 4 hours,and his brother mark can do the same (answered by lwsshak3)

Ricky can install a basic security system in 4 hours. If it takes Ricky and Mark 2 hours... (answered by awang1996)

Working together, Amy and Bob can complete a job in 12 hours, Working lone, it takes Amy... (answered by josgarithmetic)

A and B working together can complete a job in 7 1/2 hours. Working alone, A takes 8... (answered by ankor@dixie-net.com)

Jessie and Mark are planning to paint a house together. Jessie thinks that if he works... (answered by Edwin McCravy)

A can do a certain job, working alone, in 3.15 hours. Working with B, A can do the same... (answered by ankor@dixie-net.com)

Working together, Bob, Sally, and Harry can dig a hole in 3.5 hours. Working alone, Harry (answered by josmiceli)

Alex and Boy working together can complete a job in 7 1\2 hours. Working alone, Alex... (answered by edjones)