A) 12 days
B) 15 days
C) 16 days
D) 18 days
Correct Answer: B
Solution :
(b): A+B+C can together do work in \[\frac{1}{\frac{1}{20}+\frac{1}{30}+\frac{1}{60}}\]days = 10days . \[\therefore \]In 1 day, they can do 1/10 part of work. In 1 day, A can do 1/20 part work. In 2 days, A can do 1/10 part work. Since every 3rd day, B & C join A = In every 3 days, \[\frac{1}{10}+\frac{1}{10}=\frac{1}{5}\] work is done. = In 15 days\[\left( 3\times 5 \right)\], full work will be done.You need to login to perform this action.
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