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