A can do a piece of work 40 days. B can do work in 60 days. In how many days they will complete the work together?
Answers
A) 15 days
B) 16 days
C) 19 days
D) 17 days
E) 24 days

Rationale: "lcm = 120 , ratio = 40 : 60 = 2 : 3 no of days = 120 / ( 2 + 3 ) = 90 / 5 = 24 days answer : e"
Answer: E