Find the L.C.M. of 72, 108 and 2100.  Pick one.
A) 37800	B) 37600	C) 37200	D) 37500	E) none of them

Rationale: 72 = 2 ^ 3 x 3 ^ 2 , 108 = 3 ^ 3 x 2 ^ 2 , 2100 = 2 ^ 2 x 5 ^ 2 x 3 x 7 . l . c . m . = 2 ^ 3 x 3 ^ 3 x 5 ^ 2 x 7 = 37800 . answer is a .
Answer: A