Two numbers are in the ratio 4 : 5 and their L.C.M. is 180.

Two numbers are in the ratio 4 : 5 and their L.C.M. is 180. The smaller number is

Let the numbers be 4x and 5x.
Their LCM = 20x
According to the question,
20x = 180

⇒ x =	180	= 9
	20

∴ Smaller number
= 4x = 4 × 9 = 36