Question

A carpenter takes 8 hour to make an armchair while his assistant takes 12hours to do the same job. Working together, how long would they take to make the wooden armchair

Answer 1

A carpenter takes 8 hours to make an armchair while his assistant takes 12 hours to do the same job.


Let A is time taken by carpenter and B is time taken by assistant .
now when they are working together ,
time taken = AB/(A + B)

Here, A = 8 hours and B = 12 hours
so, time taken = 8 × 12/(8 + 12) = 96/20 =4.8 hrs

Answer 2

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