SOLUTION: Margaret and Kiara can finish a certain work in 3 hours. If Margaret works alone, she can finish it in 4 hours. How many hours would it take Kiara to do the work alone?

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Margaret and Kiara can finish a certain work in 3 hours. If Margaret works alone, she can finish it in 4 hours. How many hours would it take Kiara to do the work alone?      Log On


   

Question 772965: Margaret and Kiara can finish a certain work in 3 hours. If Margaret works alone, she can finish it in 4 hours. How many hours would it take Kiara to do the work alone?
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
Margaret and Kiara can finish a certain work in 3 hours. If Margaret works alone, she can finish it in 4 hours. How many hours would it take Kiara to do the work alone?
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Margaret and Kiara can finish a certain work in 3 hours.
Their work rate=1/3
Margaret works alone, she can finish it in 4 hours.
Her work rate=1/4
let x=hours Kiara can finish the job alone
Her work rate=1/x
..
sum of individual work rates=work rate working together
1%2Fx%2B1%2F4=1%2F3
1%2Fx=-1%2F4%2B1%2F3
1%2Fx=1%2F12
x=12
hours Kiara can finish the job alone=12