If 40% of a certain number is 160, then what is 20% of that number?  Choose the correct choice from the following answers:
A) 75
B) 100
C) 120
D) 30
E) 80

Rationale: "explanation : 40 % = 40 * 4 = 160 20 % = 20 * 4 = 80 answer : option e"
Answer: E