The population of a town is 20000. It increases annually at the rate of 20% p.a. What will be its population after 2 years?  Select.
A) 24440 B) 24800 C) 28400 D) 28800 E) 28600

Rationale: "explanation : formula : ( after = 100 denominator ago = 100 numerator ) 20000 * 120 / 100 * 120 / 100 = 120 * 120 * 2 = 28800 answer : option d"
Answer: D