Two friends run the New York City marathon, one friend finishes the marathon in 400 minutes while the second friend finishes the marathon in 625 minutes. What is the ratio of their speed?
Choose the correct choice from the following:	A) 10 : 12	B) 1 : 2	C) 5 :10	D) 20 : 25	E) None
Solution   Let us name the friends   as A and B.	= ( Friend A'S speed) : (Friend B's speed)   =âˆšb : âˆša   = âˆš400 : âˆš625   = 20 : 25   Answer 20 : 25
<result>D</result>
Two friends run the New York City marathon, one friend finishes the marathon in 400 minutes while the second friend finishes the marathon in 625 minutes. What is the ratio of their speed?