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Sam can mow a lawn in 40 minutes. Rocky can mow the same lawn in 120 minutes. How long does it take for both Sam and Rocky to mow the lawn if they are working together? Express your answer as a reduced fraction.

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Answer: It will take 30 minutes to mow the lawn if Sam and Rocky work together.

Explanation:

Given : Time taken by Sam to mow the lawn = 40 minutes

Time taken by Rocky to mow tha lawn = 120 minutes.

If they work together , then the time taken by them is given by :-


(1)/(t)=(1)/(40)+(1)/(120)\\\\\Rightarrow\ (1)/(t)=(3+1)/(120)\\\\\Rightarrow\ (1)/(t)=(4)/(120)=(1)/(30)\\\\\Rightarrow\ t=30

Hence, it will take 30 minutes to mow the lawn if Sam and Rocky work together.

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