Question

9 men can do a work in 12 days working 4 hours a day. In how many days can 6 men do the same work, working 8 hours a day?

Answer 1

Answer:

Answer: b. 9

Step-by-step explanation:

Let d be the number of days it took to complete the work if 6 men do the same work, working 8 hours a day

If M1 men can do the work in working H1 hours per day and M2 men can do the same work in working H2 hours per day, then

\begin{lgathered}{M_1H_1}={M_2H_2}\\\\\Rightarrow\ {9\times12\times4}=6\times8\times d\\\\\Rightarrow d=\frac{9\times12\times4}{48}\\\\\Rightarrow d=9\ days\end{lgathered}

M

1

H

1

=M

2

H

2

⇒ 9×12×4=6×8×d

⇒d=

48

9×12×4

⇒d=9 days