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 50 days to complete the same work. then Q alone can do it in Choose the correct choice:
A) 20  B) 22  C) 25  D) 27  E) 30
Work done by P and Q in 1 day = 1/10   Work done by R in 1 day = 1/50   Work done by P, Q and R in 1 day = 1/10 + 1/50 = 6/50   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 × 2 = 6/50   =&gt; Work done by P in 1 day = 3/50   =&gt; Work done by Q and R in 1 day = 3/50   Hence work done by Q in 1 day = 3/50 – 1/50 = 2/50 = 1/25   So Q alone can do the work in 25 days   Answer is 25.
<result>C</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 50 days to complete the same work. then Q alone can do it in