Question

Suhani has done 1/3rd of a job in 20 days. Megha completes the rest of the job in 10 days. In how many days can the work together do the job?
1. 16 days
2. 12 days
3. 10 days
4. 15 days
5. 13 days

Answer 1

Correct Answer - Option 2 : 12 days

Given:

Suhani does 1/3^rd of a job in 20 days

Remaining work done by Megha = (1 – 1/3)

⇒ (3 – 1)/3

⇒ 2/3^rd in 10 days

Concept used:

If a person does a work in ‘n’ days, then one day work will be 1/n part of total work.

Total time taken for one work = number of days/part of the work

Calculation:

One work done by Suhani = 10 × 3/2

⇒ 15 days

Then one day work by Suhani = 1/15 part of total work

One work done by Megha = 20 × 3

⇒ 60 days

Then one day work by Megha = 1/60 part of total work

Now, the one day work by Suhani and Megha = one day work by Suhani + one day work by Megha

⇒ 1/15 + 1/60

⇒ (4 + 1)/60

⇒ 5/60

⇒ 1/12

Then one work done by both Suhani and Megha = 12 days

∴ The work done by both when work together in 12 days