Bob wants to run a mile in the same time as his sister. If Bob’s time for a mile is currently 10 minutes 40 seconds and his sister’s time is currently 9 minutes 42 seconds, by what percent does Bob need to improve his time in order run a mile in the same time as his sister?  Choices:  A) 3%  B) 5%  C) 8%  D) 9%  E) 12%
Bob's time = 640 secs.   His sis' time = 582 secs.   Percent increase needed = (640-582/640) * 100 = 58/640 * 100 = 9%. Ans (9%).
<result>D</result>
Bob wants to run a mile in the same time as his sister. If Bob’s time for a mile is currently 10 minutes 40 seconds and his sister’s time is currently 9 minutes 42 seconds, by what percent does Bob need to improve his time in order run a mile in the same time as his sister?