if Juan takes 15 seconds to run y yards, how many seconds will it take him to run x yards at the same rate?
Pick
A) 11x/y	B) 11y/x	C) 15x/y	D) 11/xy	E) xy/11
Answer is C.   The rate of running hards: 15 minutes per y hards.   Thus the time for running x hards = x hards * 15 minutes/y hards = 15x/y
<result>C</result>
if Juan takes 15 seconds to run y yards, how many seconds will it take him to run x yards at the same rate?