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 8 miles per hour while the second runner jogs due east at a constant rate that is 8 miles per hour faster than the first runner's rate. How far apart, to the nearest mile, will they be after 1/2 hour ? Choose the correct answer.
A) 6
B) 7
C) 8
D) 12
E) 9
If runner 1 is going north and runner 2 is going east they are like two sides of a 90 degree triangle.   Side 1 = 8 m/h --&gt; 4 m in 1/2 hr   Side 2 = 16 m/h --&gt; 8 m in 1/2 hr   to complete this right angle triangle   d^2 = 4^2 + 8^2   d^2 = 80   = ~ 9   Answer option 9
<result>E</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 8 miles per hour while the second runner jogs due east at a constant rate that is 8 miles per hour faster than the first runner's rate. How far apart, to the nearest mile, will they be after 1/2 hour ?