If 0.75 of a number is equal to 0.025 of another number, the ratio of the numbers is :
Choices:
A) 2 : 3
B) 3 : 4
C) 1 : 30
D) 20 : 3
E) 30 : 7

Rationale: "0.75 a = 0.025 b - > a / b = 0.025 / 0.75 = 25 / 750 = 1 / 30 : . a : b = 1 : 30 answer : c"
Answer: C