If 70% of an equal to 40% of b, then ratio between a and b is? Pick one
A) 4 : 7 B) 4 : 9 C) 4 : 2 D) 4 : 1 E) 4 : 5

Rationale: explanation : 70 a = 40 b a : b = 4 : 7 answer : a
Answer: A