Question

10 labourers working 8 hours a day can build a wall in 6 days. How many labourers are
needed to build the same wall in 4 days if they work 5 hours each day?

Answer 1

10×8hours=the total amount of hours spent one day

                =80hours

80hours×6=the total amount of hours spent overall

                 =480hours

5hours×4=the amount of hours limit

               =20hours

480hours÷20hours=the amount of workers needed

                               = 24 workers

24 workers are needed.

You’ll get it, don’t worry!

Answer 2

Answer:

Given:

6 labourers can build a wall in 10 days.

Formula used:

Men × day = Total work

Calculation:

Total work = 6 × 10 = 60 unit.

According to the question,

Double the efficiency are needed to build 3 such walls in 5 days

⇒ Total unit = 60 × 3 = 180 unit

⇒ Men × 2 × 5 = 180

⇒ Men = 18

∴ The number of labour is 18.