If 2A = 3B and 4B = 5C, then A : C is?

∵ 2A = 3B and 4B = 5C
⇒ 8A = 12B and 12B = 15C
⇒ 8A = 12B = 15C = x
∴ A = x/8, B = x/12, C = x/15
So, A : C = x/8 : x/15 = 15 : 8