SSC CHSL 2022 PYQ — Question 72

SSC CHSL - 26 May 2022 - Shift 2 • Quantitative Aptitude • Q72

A man takes 16 days to complete a project. A woman does the same work in 12 days. They started the work together on alternate days and the man worked on the first day. How much time will they take to complete the work?

Show answer & explanation

Correct answer: B

Explanation

The correct answer is option 2 i.e. 55/4 days 

Concept Used :

Total Work = Efficiency × Time

Given that, Man can do the work in 16 days 

And women can do it in 12 days

Let the total work to be done be LCM of (16, 12) = 48 units

Efficiency of a man = 48/16 = 3 units/day

Efficiency of a woman = 48/12 = 4 units/day

They work alternatively, So the work completed in 2 days = 7 units

Similarily work done in 12 days = 42 units

Now remaining work = 48 - 42 = 6 units

Now a man works for 1 day, the amount of work done = 3 units

Now, remaining work = 3 units

So, the time required by a woman to complete 3 units of work = 3/4 days

So, the total number of days to complete the work = 13 + 3/4 = 55/4.

Hence the required time to complete the work is 55/4 days.