At a contest with 2000 participants, 1/2 of the people are aged 16 to 18. Next year, the number of people aged 16 to 18 will increase by 1/4. After this change, what percentage of the total 2000 people will the 16- to 18- year-olds represent?	Choose the correct choice:
A) 62.50 %  B) 60 %  C) 70 %  D) 65 %  E) 66 / 3 %

Rationale: i just wanted to mention a couple of things here : * this is a pure ratio question ; the number 2000 is completely irrelevant , and you can ignore it if you like . when we increase something by 1 / 4 , we are multiplying it by 1 + 1 / 4 = 5 / 4 , so the answer here must be ( 1 / 2 ) * ( 5 / 4 ) = 5 / 8 = 62.50 % . answer : a
Answer: A