hree number are in the ratio of 3 : 4 : 5 and their L.C.M. is 2400. Their H.C.F. is:  Choose the correct choice from the following answers:
A) 40
B) 50
C) 60
D) 70
E) 80

Rationale: let the numbers be 3 x , 4 x and 5 x . then , their l . c . m . = 60 x . so , 60 x = 2400 or x = 40 . the numbers are ( 3 x 40 ) , ( 4 x 40 ) and ( 5 x 40 ) . hence , required h . c . f . = 40 . answer : a
Answer: A