Question

4 people can dig a hole 20m deep in 3 hours. How long will 25 people take to dig a hole 50m deep?

Answer 1

25 people can dig the hole of 50 m deep in $1.2$ hours

Explanation

4 people can dig a hole 20 m deep in 3 hours

So, 1 people can dig a hole 20 m deep in (3×4)hours= 12 hours [If the number of people decreases, then the time taken to dig the hole will increase]

and 1 people can dig a hole 1 m deep in ($\frac{12}{20}$)hours = $\frac{3}{5}$ hours = 0.6 hours

Now, if 1 people dig the hole of 50 m , then the time needed = (0.6×50) hours = 30 hours

So, 25 people can dig the hole of 50 m deep in = $\frac{30}{25}= \frac{6}{5}= 1.2$ hours