P is able to do a piece of work in 5 days and Q can do the same work in 10 days. If they can work together for 3 days, what is the fraction of work completed?  Options.
A) 13/10  B) 4/5  C) 11/10  D) 7/10  E) 9/10
9/10xplanation :   Amount of work P can do in 1 day = 1/5   Amount of work Q can do in 1 day = 1/10   Amount of work P and Q can do in 1 day = 1/5 + 1/10 = 3/10   Amount of work P and Q can together do in 3 days = 3 × (3/10) = 9/10   Answer : Option 9/10
<result>E</result>
P is able to do a piece of work in 5 days and Q can do the same work in 10 days. If they can work together for 3 days, what is the fraction of work completed?