Time And Work Ques 22
Question-
The respective ratio of the time taken by $A$ and $B$ individually to finish a piece of work is $4: 5$. The respective ratio of the time taken by $B$ and $C$ individually to finish the same piece of work is $3: 4$. If $A$ and $C$ together can finish $\frac{1}{3} rd$ of the same piece of work in 5 days, in how many days can $B$ alone finish the same piece of work?
(1) 32
(2) 27
(3) 40
(4) 24
(5) 30
(IBPS RRBs Officers CWE (Prelim Exam) 10.09.2017)
Show Answer
Correct Answer: (5)
Solution: (5)
$A: B=4: 5=12: 15$
B : $C=3: 4=15: 20$
$\therefore A: B: C=12: 15: 20$
Time taken by $A$ and $C$ in doing 1 work $=15$ days
$\therefore \frac{1}{12 x}+\frac{1}{20 x}=\frac{1}{15}$
$\Rightarrow \frac{5+3}{60 x}=\frac{1}{15}$
$\Rightarrow \frac{8}{4 x}=1$
$\Rightarrow 4 x=8$
$\Rightarrow x=\frac{8}{4}=2$
$\therefore$ Time taken by $B=15 x$ $=15 \times 2=30$ days
BETA
