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Tom can do a job in 4 hours while Sam can do it in 6 hours. How many hours would it take to complete this job if they work together?

User Jasekp
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1 Answer

3 votes

Answer:

They will both do the job in 2.4 or 12/5 or 2 2/5 hours

Explanation:

Tom can do a job in 4 hours while Sam can do the same job in 6 hours. The hours both of them can complete this job together can be calculated below.

Tom can do the job in 4 hours . In 1 hours he will be able to do 1/4 of the job.

Sam can do the job in 6 hours . In 1 hours he will be able to do 1/6 of the job.

Let

the combine time = a hrs

Since both of them can do the job in a hours. In 1 hour they will be able to do 1/a of the job.

Therefore,

1/4 + 1/6 = 1/a

(6 + 4)/24 = 1/a

10/24 = 1/a

cross multiply

10a = 24

divide both sides by 10

a = 24/10

a = 2.4 or 12/5 or 2 2/5 hours

They will both do the job in 2.4 or 12/5 or 2 2/5 hours

User Kinesh
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