If 10 workers can dig a well in 4 days, then how many workers will be required to dig the same well in half a day?

Explanation

In 4 days, 10 workers together dig 1 well. In 1 day, $(4 \times 10)$ workers together dig 1 well. In 1/2 day, $(4 \times 10 \times 2)$ workers together dig 1 well. = 80 workers Second Method – $$\frac{M_1 D_1}{W_1} = \frac{M_2 D_2}{W_2}$$ $$\frac{10 \times 4}{1} = \frac{M_2 \times 1}{1 \times 2}$$ $M_2 = (10 \times 4 \times 2)$ men = 80 men