Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.

Problem: last year elaine spent 20 % of her annual earnings on rent. this year she earned 20 % more than last year and she spent 30 % of her annual earnings on rent. the amount she spent on rent this year is what percent of the amount spent on rent last year ?
Options: a. 185.5, b. 180.0, c. 167.5, d. 172.5, e. 177.5
b

Problem: bob wants to run a mile in the same time as his sister. if bob ’ s time for a mile is currently 11 minutes 20 seconds and his sister ’ s time is currently 9 minutes 36 seconds, by what percent does bob need to improve his time in order run a mile in the same time as his sister ?
Options: a. 3 %, b. 5 %, c. 8 %, d. 10 %, e. 15 %
e

Problem: the total number of digits used in numbering the pages of a book having 369 pages is
Options: a. 732, b. 990, c. 999, d. 1305, e. 1405

c