4 men and 6 women can complete a job in 8 days, while 3 men and 7 women can complete it in 10 days. In how many days will 10 women take to complete the same job?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 40 days
Step 1: Establish the Efficiency Ratio
Let the work done by 1 man in one day be $M$ and by 1 woman be $W$. Since the total work remains the same, we can set up the following equation:
$(4M + 6W) \times 8 = (3M + 7W) \times 10$
Simplify the equation:
$32M + 48W = 30M + 70W$
$32M - 30M = 70W - 48W$
$2M = 22W$
$1M = 11W$
This tells us that 1 man does as much work as 11 women.
Step 2: Calculate Total Work in terms of Women
Now, substitute the value of $M$ into the first scenario to find the total work units:
$\text{Total Work} = (4M + 6W) \times 8$
$\text{Total Work} = [4(11W) + 6W] \times 8$
$\text{Total Work} = (44W + 6W) \times 8$
$\text{Total Work} = 50W \times 8 = \mathbf{400W \text{ units}}$
Step 3: Find Time Taken by 10 Women
Now, we find how many days 10 women will take to complete these 400 units of work:
$\text{Days} = \frac{\text{Total Work}}{\text{Daily Work of 10 Women}}$
$\text{Days} = \frac{400W}{10W}$
$\text{Days} = \mathbf{40 \text{ days}}$