A does 
of a work in 9 days. Then B joined him and they together completed the remaining work in 6 days. B alone can finish the whole work in
Show answer & explanation
Correct answer: D
Explanation
The correct option is 4.
If A can complete of work in 9 days,
then he can complete whole work in 
= 22.5 days.
Let B take x number of days to complete the work.
A/c to question,
x = 18 days.
So , the answer would be option d) 18 days