9. On level farmland, two runners leave at the same time from the intersection of two country roads. One runner jogs due north at a constant rate of 6 miles per hour while the second runner jogs due east at a constant rate that is 2 miles per hour faster than the first runner's rate. How far apart, to the nearest mile, will they be after 1/2 hour ? Pick.
A) 6 B) 7 C) 5 D) 12 E) 14
If runner 1 is going north and runner 2 is going east they are like two sides of a 90 degree triangle.   Side 1 = 6 m/h --&gt; 3 m in 1/2 hr   Side 2 = 8 m/h --&gt; 4 m in 1/2 hr   to complete this right angle triangle   d^2 = 4^2 + 3^2   d^2 = 25   = 5   Answer option 5
<result>C</result>
9. On level farmland, two runners leave at the same time from the intersection of two country roads. One runner jogs due north at a constant rate of 6 miles per hour while the second runner jogs due east at a constant rate that is 2 miles per hour faster than the first runner's rate. How far apart, to the nearest mile, will they be after 1/2 hour ?