Question

P, Q and R can do a work in 12, 24 and 32 days respectively. They all begin together. P continues to work till it is finished. R left after 4 days and Q, one and half day before its completion. In what time is the work finished?

• A. 10.5 days
• B. 7.5 days
• C. 9 days
• D. 12 days
• E. None of these

Answer 1

The correct option is B

7.5 days

Assume the work is done in ‘x’ days.

$\therefore \frac{x}{12}+\frac{x-1.5}{24}+\frac{4}{32}=1$

$\Rightarrow x=7.5$
Therefore, the work is finished in 7.5 days.