The compound ratio of 2:3, 3:2 and 4:5?  Pick one
A) 1 : 9 B) 1 : 7 C) 1 : 2 D) 4 : 5 E) 1 : 4

Rationale: "2 / 3 * 3 / 2 * 4 / 5 = 4 / 5 = 4 : 5 answer : d"
Answer: D