P can complete a task in 6 days, Q can destroy it in 4 days. P works for 3 days, then Q joins for 2 days. In how many days will P finish the remaining work alone?

Question

Accepted Answer

1. Rates: P does $1/6$ of the job per day. Q destroys $1/4$ per day.

2. P works 3 days: done = $3	imes	frac{1}{6}=	frac{1}{2}$.

3. Q works 2 days (destroying): removed = $2	imes	frac{1}{4}=	frac{1}{2}$. So work done becomes $	frac{1}{2}-	frac{1}{2}=0$. The whole job is left.

4. P must do the whole job alone: time = $1\div	frac{1}{6}=6$ days.

FINAL_ANSWER: a

Answer

Answer

Answer