RRB ALP 2013 Ques 80
Question: A does half as much work as B in one-sixth of the time. If together they take 10 days to complete a work, how much time shall B alone take to do it?
Options:
A) 70 days
B) 30 days
C) 40 days
D) 50 days
Show Answer
Answer:
Correct Answer: C
Solution:
- Let the time taken by B alone to complete the work be $ x $ days.
$ \therefore $ Time taken by A to complete $ \frac{1}{2} $ work $ =\frac{x}{6} $ days
$ \therefore $ Work of A for 1 day $ =\frac{1}{2}\times \frac{6}{x}=\frac{3}{x} $ and Work of B for 1 day $ =\frac{1}{x} $
$ \Rightarrow $ $ \frac{3}{x}+\frac{1}{x}=\frac{1}{10} $
$ \Rightarrow $ $ \frac{4}{x}=\frac{1}{10} $ $ x=40days $ .
BETA
