Three men can complete a job in 3 days, working 3 hours a day. In how many days can 9 men complete it working 1 hour a day?

3

The correct answer is Option (3) → 3

To find the number of days, we can use the work formula:

$\frac{M_1 \times D_1 \times H_1}{W_1} = \frac{M_2 \times D_2 \times H_2}{W_2}$

Since the job (work $W$) remains the same, the formula simplifies to:

$M_1 \times D_1 \times H_1 = M_2 \times D_2 \times H_2$

Given data:

• $M_1 = 3$ men, $D_1 = 3$ days, $H_1 = 3$ hours/day
• $M_2 = 9$ men, $H_2 = 1$ hour/day, $D_2 = ?$

Calculation:

$3 \times 3 \times 3 = 9 \times D_2 \times 1$

$27 = 9 \times D_2$

$D_2 = \frac{27}{9} = 3$