A) 27 days
B) 20 days
C) 30 days
D) 25 days
Correct Answer: C
Solution :
Let the time taken by *B' alone to finish work is x days. Then, the time taken by 'A' alone to finish the work is \[(x-10)\]days. Now, \[\frac{1}{x}+\frac{1}{x-10}=\frac{1}{12}\] \[\frac{x-10+x}{x(x-10)}=\frac{1}{12}\] \[24{{x}^{2}}-120={{x}^{2}}-10x\] \[{{x}^{2}}-34x+120=0\] On solving, x=30, 4 Hence, x=30 daysYou need to login to perform this action.
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