**Question:**

*Tick (✓) the correct answer:*

3 men or 5 women can do a work in 12 days. How long will 6 men and 5 women take to do it?

(a) 6 days

(b) 5 days

(c) 4 days

(d) 3 days

**Solution:**

(c) 4 days

Three men can complete the work in 12 days.

Thus, one man can complete the work in 36 days.

Rate of work done by one man in 1 day $=\frac{1}{36}$

Similarly, rate of work done by one woman in 1 day $=\frac{1}{5 \times 12}=\frac{1}{60}$

Now, six men will do $\frac{6}{36}$, i.e., $\frac{1}{6}$ unit of work in a day.

Five women will do $\frac{5}{60}, \mathrm{i}, \mathrm{e} ., \frac{1}{12} \mathrm{unit}$ of work in a day.

$\therefore$ Total work done in 1 day $=\frac{1}{6}+\frac{1}{12}=\frac{1}{4}$ unit

Thus, six men and five women will take 4 days to complete the work.

The work can be completed in 4 days.