Question

Ramu can complete a job in 8 days, Shyamu can complete the same job in 12 days. However , Monu takes 12 days to complete $\frac{3}{4}$th of the same job. Ramu works for 2 days and then leaves the job,. The number of days that will be taken by Shaymu and Monu to balance together is

• A. 4.2
• B. 5.1
• C. 6.2
• D. 6.5

Answer 1

The correct option is B 5.1

Ramu's one days job = $\frac{1}{8}$ Shyamu's one days' job = $\frac{1}{12}$
$\frac{3}{4}th$ of the job can be done by Monu in 12 days $\therefore$ Whole job can be done by Monu in $12\times \frac{4}{3}$ days = 16 days
$\therefore$ Monu's one days' job = $\frac{1}{16}$ Ramu's two days' job = $2\times \frac{1}{8}=\frac{1}{4}$ Remaining job = $1-\frac{1}{4}=\frac{3}{4}$
(Shyamu's + Monu's) one days' job = $\frac{1}{12}+\frac{1}{16}=\frac{4+3}{48}=\frac{7}{48}$
$\frac{7}{48}$ of the job can be finished by Shyamu and Monu in 1 day
$\therefore$ $\frac{3}{4}$ of the job can be finished by Shyamu and Monu in $\frac{48}{7}\times \frac{3}{4}=\frac{36}{7}=5.1$ days