Quantitative Aptitude Ques 531

Question: A can do a piece of work in 12 days and B in 15 days. They work together for 5 days and then B left. The days taken by A to finish the remaining work is [NICL (AO) 2015]

Options:

A) 3 days

B) 5 days

C) 10 days

D) 12 days

E) 15 days

Show Answer

Answer:

Correct Answer: A

Solution:

  • [a] Time taken by A and B both to complete the work $ =\frac{12\times 15}{27}=\frac{20}{3}days $

$ \therefore $ In 1 day, they can complete $ =\frac{3}{20}part $

$ \therefore $ In 5 day, then can complete $ =5\times \frac{3}{20}=\frac{3}{4}part $ Remaining work $ =1-\frac{3}{4}=\frac{1}{4} $ Time taken by A to complete the work $ =\frac{\frac{1}{4}}{\frac{1}{12}}=3days $