A can do a piece of work in 8 days, while B can do it in 18 days. In how many days will the work be completed if they both work on alternate days starting with B?

Question

Question

This question was previously asked in

SSC CGL 2023 Tier-I Official Paper (Held On: 21 Jul 2023 Shift 4)

Answer 1

Given:

A can do a piece of work in 8 days, while B can do it in 18 days.

Concept used:

Efficiency = (Total work / Total time taken)

Efficiency = work done in a single day

Calculation:

Let the total work is the 72 units (LCM of 8 and 18)

The efficiency of A is 72 / 8 = 9 units

The efficiency of Bi is 72 / 18 = 4 units

In 2 days they do 9 + 4 = 13 units

They do 65 units of work in 5× 2 = 10 days

Then B does 4 units in 1 day

Then A does 3 units in 1/3 day

Total number of days will be 10 + 1 + 1/3 = 11$\frac{1}{3}$ $\frac{3}{4}$