# A paricular job can be completed by a team of 10 men in 12 days. The same job can be completed by a team of 10 women in 6 days. How many days are needed to complete the job if the two teams work together?

A paricular job can be completed by a team of 10 men in 12 days. The same job can be completed by a team of 10 women in 6 days. How many days are needed to complete the job if the two teams work together?
[A]18 days
[B]9 days
[C]6 days
[D]4 days

4 days
According to the question,
10 men’s one day’s work $= \frac{1}{12}$
∴ 1 man one day’s work $= \frac{1}{12\times 10} = \frac{1}{120}$
Similarly,
1 woman one day’s work $= \frac{1}{6\times 10} = \frac{1}{60}$
∴ (1 man + 1 woman)’s one day’s work $= \frac{1}{120}+\frac{1}{60}$
$= \frac{1+2}{120} = \frac{3}{120} = \frac{1}{40}$
∴ (10 man + 10 woman)’s one day’s work $= \frac{10}{40} = \frac{1}{4}$
Therefore, both the team can finish the whole work in 4 days.
Hence option [D] is the right answer.