Two horses begin running on an oval course at the same time. One runs each lap in 4 minutes; the other takes 16 minutes to run each lap. How Many minutes after the start will the faster horse have a one lap lead?
Choose the correct option:  A) 36  B) 12  C) 16/3  D) 4  E) 3
The rate of the faster horse is 1/4 lap/minute;   The rate of the slower horse is 1/16 lap/minute;   Their relative rate is 1/4-1/16=3/16 lap/minute;   The faster horse to gain one full lap will need time=distance/rate=1/(3/16)=16/3 minutes.   Answer: 16/3
<result>C</result>
Two horses begin running on an oval course at the same time. One runs each lap in 4 minutes; the other takes 16 minutes to run each lap. How Many minutes after the start will the faster horse have a one lap lead?