Question

a, b, c can complete a certain work in 8,10,12 days respectively. in how many days would all of them complete the same work, if they work together? (1/8+1/10+1/12)

Answer 1

A's 1 day work = 1/8th part

B's 1 day part = 1/10th part

C's 1 day work = 1/12th part

(A+B+C)'s 1 day work  = 1/8+1/10+1/12      (Taking L.C.M of 8,10 and 12)

                                    = (15+12+10)/120 = 37/120

They can together do the same work in 120/37 days =  3 9/37 days