If A:B is 3:4 and B:C is 4:5 then A:C is equal to  Choose the correct option:
A) 1 : 3 B) 3 : 5 C) 3 : 4 D) 3 : 7 E) 1 : 5

Rationale: the two ratios given are having the same number 4 for b in both the ratios . hence - a : b = 3 : 4 b : c = 4 : 5 = > a : c = 3 : 5 answer b
Answer: B