P and Q together can do a piece of work in 4 days. If P does twice as much work as Q in a given time, find how long P alone would take to do the work? P और Q किसी काम को एक साथ 4 दिनों में करते है। यदि दिये समय में P, Q से दो गुना काम करे तो P अकेले उस काम को कितने समय में करेगा?

P and Q together complete work in 4 days, so their combined rate is 1/4 of the work per day. Since P does twice as much work as Q in the same time, let Q's rate be x and P's rate be 2x. Then 3x = 1/4, meaning x = 1/12. Therefore P's rate is 2/12 = 1/6 of the work per day, so P alone takes 6 days. The key insight is that work rates add up when people work together.