Question

i spend 20 hour to clean my garden. how long will it take if 4 people (with the same efficiency) come to join me​

Answer 1

1 person = 20 hour

1 *20=20

4 person = 4 * x = 20

x = 20/4= 5

5 hours

Answer 2

It will take 4 hours.

Given data :

I compete the task in = 20 hours

4 people joins with same efficiency

So,

The total persons working now

= (Me + 4 people)

= (1+4)

= 5

Now,

1 people can finish in = 20 hours

5 people can finish in = 20/5 = 4 hours (answer)