A) 20 days
B) \[22\frac{1}{2}\]days
C) 25 days
D) 30 days
Correct Answer: B
Solution :
Suppose B takes x days to finish the job. Then, A takes \[(x-60)\]days to finish it. Work done by A in 1 day = 3 times work done by B in 1 day \[\frac{1}{x-60}=\frac{3}{x}\Rightarrow 3x-180=x\] \[\Rightarrow \] \[2x=180\Rightarrow x=90\] B takes 90 days and A takes 30 days to finish work. (A+ B)?s 1 day?s work \[=\left( \frac{1}{30}+\frac{1}{90} \right)=\frac{4}{90}=\frac{2}{45}\] Working together they finish the work in\[\frac{45}{2}\]days \[=22\frac{1}{2}\]days.You need to login to perform this action.
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