X does a work in 40 days. Y does the same work in 60 days. In how many days they together will do the same work?	Options: A) 10 B) 12 C) 24 D) 30 E) 15

Rationale: "x ' s 1 day ' s work = 1 / 40 y ' s 1 day ' s work = 1 / 60 ( x + y ) ' s 1 day ' s work = ( 1 / 40 + 1 / 60 ) = 1 / 24 both together will finish the work in 24 days . correct option is c"
Answer: C