Question

Four people can paint a fence in 3 hours. How long would it take six people to paint the fence assuming they all work at the same rate?

Hint: This is either direct or inverse proportions.

Answer 1

Answer: 2 hour

Solution:

Step 1. This is the case of Inverse proportion i.e. more people will paint a fence in less hours. So. assuming they all work at the same rate,

=> Work done by 4 people in 3 hour = Full work

=> Work done by 1 people in 3 hour = 1/4 part of work

=> Work done by 1 people in 1 hour = 1/12 part of work

Step 2. We know, work done by 1 people in 1 hour = 1/12 part of work. So,

=> Work done by 6 people in 1 hour = 6 x 1/12 part of work

=> Work done by 6 people in 1 hour = 1/2 part of work

Step 3. Now, we know, 1/2 part of work is done by 6 people in 1 hour.

=> 1/2 part of work is done by 6 people in = 1 hour

So, full work is done by 6 people in = 1\(1/2) hour =

full work is done by 6 people in = 2 hour