Triathlete Dan runs along a 2-mile stretch of river and then swims back along the same route. If Dan runs at a rate of 10 miles per hour and swims at a rate of 5 miles per hour, what is his average rate for the entire trip in miles per minute?
Choose the correct choice from the following answers:  A) 1/9  B) 2/15  C) 3/15  D) 1/4  E) 3/8
Dan travels 4 miles round trip.   Running part: (2/10 = 1/5*60= 
<gadget id="calculator">1/5*60</gadget>
<output>12</output>
12 minutes)   Swimming Part: (2/5= 2/5*60= 
<gadget id="calculator">2/5*60</gadget>
<output>24</output>
24 minutes)   4 miles in (12+24) minutes   4/36= 1/9 mile per minute   1/9nswer: 1/9 mile per minute
<result>A</result>
Triathlete Dan runs along a 2-mile stretch of river and then swims back along the same route. If Dan runs at a rate of 10 miles per hour and swims at a rate of 5 miles per hour, what is his average rate for the entire trip in miles per minute?