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: 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 sector of a circle has radius of 24 cm and central angle 135 o. find its perimeter ?
Options: a. 91.5 cm, b. 11.5 cm, c. 104.6 cm, d. 92.5 cm, e. 99.5 cm
c

Problem: the pilot of a small aircraft with a 60 - gallon fuel tank wants to fly to cleveland, which is 480 miles away. the pilot recognizes that the current engine, which can fly only 10 miles per gallon, will not get him there. by how many miles per gallon must the aircraft ’ s fuel efficiency be improved to make the flight to cleveland possible ?
Options: a. 5, b. 12, c. 2, d. 4, e. 6

c