Question: A and B working separately can do a piece of work in 10 days and 15 days, respectively. If they work on alternate days beginning with A, in how many days will the work be completed?
Options:
A) 18
B) 13
C) 12
D) 6
Show Answer
Answer:
Correct Answer: C
Solution:
- Work done by (A + B) in two days
$ =\frac{1}{10}+\frac{1}{15}=\frac{3+2}{30}=\frac{5}{30}=\frac{1}{6} $
$ \therefore $ Work done by (A + B) in one day $ =\frac{1}{12} $
Hence, (A + B) can complete the work in 12 days,