Time And Work Ques 25
Question-
A can complete a work in 36 days. $B$ is $33.33 \%$ more efficient than A. In how many days both complete the same work if they work on alternate days starting with A?
(1) 27 days
(2) 32 days
(3) 29 days
(4) 31 days
(5) None of these (IBPS RRBs Officer CWE
(Main Exam) 05.11.2017)
Show Answer
Correct Answer: (4)
Solution: (4)
$B$ is $\frac{100}{3} \%$ more efficient than $A$.
Time taken by $A=36$ days
$\therefore$ Time taken by $B$ $=36 \times \frac{1}{\left(100+\frac{100}{3}\right) \%}$ $=36 \times \frac{1}{\left(\frac{400}{3}\right) \%}$ $=36 \times \frac{3}{4}=27$ days
$(A+B)$ ’s 2 days’ work $=\frac{1}{27}+\frac{1}{36}=\frac{4+3}{108}=\frac{7}{108}$
$(A+B)$ ’s 30 days’ work $=\frac{15 \times 7}{108}=\frac{105}{108}$
Remaining work $=1-\frac{105}{108}$ $=\frac{3}{108}=\frac{1}{36}$
Now this part of work is done by A in 1 day.
$\therefore$ Total time taken $=30+1$ $=31$ days
BETA
