The compound ratio of 2:3, 3:4 and 4:5?	Select the correct option:  A) 1 : 2  B) 2 : 5  C) 3 : 4  D) 3 : 5  E) 3 : 9

Rationale: 2 / 3 * 3 / 4 * 4 / 5 = 2 / 5 2 : 5 answer : b
Answer: B