If the population of a certain country increases at the rate of one person every 15 seconds, by how many persons does the population increase in 55 minutes?  Pick:
A) 80	B) 100	C) 150	D) 180	E) 220

Rationale: "since the population increases at the rate of 1 person every 15 seconds , it increases by 4 people every 60 seconds , that is , by 4 people every minute . thus , in 55 minutes the population increases by 55 x 4 = 220 people . answer . e ."
Answer: E