Quantitative Aptitude Ques 2414
Question: A is 50% as efficient as B. C does half of the work done by A and B together. If C alone does the work in 40 days, then A, B and C together can do the work in
Options:
A) $ 13\frac{1}{3} $ days
B) 15 days
C) 20 days
D) 30 days
Show Answer
Answer:
Correct Answer: A
Solution:
- (A’s 1 day’s work): (B’s 1 day’s work) = 150: 100 = 3: 2 Let A’s and B’s 1 day’s work be 3x and 2x, respectively. Then, C’s 1 day’s works $ =( \frac{3x+2x}{2} )=\frac{5x}{2} $
$ \therefore $ $ \frac{5x}{2}=\frac{1}{40} $
$ \Rightarrow $ $ x=( \frac{1}{40}\times \frac{2}{5} )=\frac{1}{100} $ A’s 1 day’s work $ =\frac{3}{100}, $ B’s 1 day’s work $ =\frac{1}{50}, $ C’s 1 day’s work $ =\frac{1}{40} $ $ (A+B+C)’s $ 1 day’s work $ =( \frac{3}{100}+\frac{1}{50}+\frac{1}{40} )=\frac{15}{200}=\frac{3}{40} $ So, A, B and C are together can do the work in $ \frac{40}{3} $ $ =13\frac{1}{3}days $
BETA
