Time And Work Ques 26
Question-
24 girls work for 4 days on a project and complete one-ninth of it. 30 boys work for the next $x$ days and complete one-third of it. If after ‘$x+4$’ days, 24 girls and 30 boys work together and complete the remaining work in $6 \frac{2}{3}$ days, how many days will 30 boys take to complete the whole work?
(1) 21
(2) 20
(3) 18
(4) 27
(5) 24
(IBPS SO (IT Officer) CWE (Prelim Exam) 30.12.2017)
Show Answer
Correct Answer: (3)
Solution: (3)
$\because 24$ girls do $\frac{1}{9}$ th of project in 4 days.
$\therefore 24$ girls will do 1 work in 36 days.
Again, remaining work $=1-\frac{1}{9}-\frac{1}{3}$ $=\frac{9-1-3}{9}=\frac{5}{9}$
$\because$ (24 girls +30 boys) do $\frac{5}{9}$ work in $\frac{20}{3}$ days.
$\because$ (24 girls +30 boys) will do 1 work in $\frac{20}{3} \times \frac{9}{5}=12$ days.
$\therefore$ One day’s work of 30 boys $=\frac{1}{12}-\frac{1}{36}$ $=\frac{3-1}{36}=\frac{2}{36}=\frac{1}{18}$
$\therefore$ Required time $=18$ days
BETA
