P can do a work in the same time in which Q and R together can do it. If P and Q work together, the work can be completed in 10 days. R alone needs 35 days to complete the same work. then Q alone can do it in	Choose the correct answer:
A) 20 B) 22 C) 25 D) 28 E) 30
Work done by P and Q in 1 day = 1/10   Work done by R in 1 day = 1/35   Work done by P, Q and R in 1 day = 1/10 + 1/35 =9/70   But Work done by P in 1 day = Work done by Q and R in 1 day . Hence the above equation can be written as Work done by P in 1 day Ã— 2 = 9/70   =&gt; Work done by P in 1 day = 9/140   =&gt; Work done by Q and R in 1 day = 9/140   Hence work done by Q in 1 day = 9/140â€“ 1/35 = 1/28   So Q alone can do the work in 28 days   Answer is 28.
<result>D</result>
P can do a work in the same time in which Q and R together can do it. If P and Q work together, the work can be completed in 10 days. R alone needs 35 days to complete the same work. then Q alone can do it in