A can do a work in 15 days and B in 20 days. If they work on it together then in how many days required to complete the work?  Choose the correct option
A) 300/31  B) 300/35  C) 300/21  D) 300/15  E) 300/20
Person ( A ) ( 300/35 ) ( A+300/35 )   Time - ( 15 ) ( 20 ) (300/35)   Rate - ( 20 ) ( 15 ) ( 35 )   Work -(300) (300) (300)   therefore A+300/35 requires (300/35) days to complete entire work   = 300/35   Answer is 300/35
<result>B</result>
A can do a work in 15 days and B in 20 days. If they work on it together then in how many days required to complete the work?