Question

2 person can complete piece of work in 9 days. how many more persons are needed to complete double work in 12 days? how to calculated this problem

Answer 1

HEre we have formula M1*D1/W1=M2*D2/W2

2*9/w=(2+x)*12/2w

from this we get x=1

Hence additionally 1 person is needed to complete the work which is twice the original work in 12 days.

Answer 2

2 person take 9 days

If the work is doubled, the time needed is doubled

2 person will take 9 x 2 = 18 days

2 person takes 18 days

1 person will take 2 x 18 = 36 days

1 person need 36 days

If we have 12 days, number of people  needed = 36 ÷ 12 = 3

Number of additional person needed = 3 - 2 = 1

Answer: 1 more person