SSC CGL 2022 PYQ — Question 64

The correct answer is Option 2 i.e. $12{{1} \over4}$

Given:

Time taken by A alone = 10 days

Time taken by B alone = 16 days

Explanation:

Time taken by A to complete the work = 10 days

So, part of work done by A in 1 day = 1/10

Time taken by B to complete the work = 16 days

So, part of work done by B in 1 day = 1/16

Now, the part of work done by (A + B) in 2 days = (1/10 + 1/16) = 13/80

Now, let the total work to be done by (A + B) be 80 units.

Efficiency of A = 8 units/day

Efficiency of B = 5 units/day

The work done by (A + B) in 2 days is 13 units.

Now, work done by (A + B) in (2 × 6) days is (13 × 6) units

So, work done by (A + B) in 12 days is 78 units.

Now A will come to work and complete the remaining 2 units work in 2/8 days = 1/4 days.

So, the total work will be done in $12{{1} \over4}$ days.