If you walk for 45 minutes at a rate of 4 mph and then run f

If you walk for 45 minutes at a rate of 4 mph and then run for 30 minutes at
a rate of 10 mph, how many miles have gone at the end of one hour and 15
minutes ?
(A) 3.5 miles (B) 8 miles (C) 9 miles (D) 25 1/3 miles

Solution

3/4*15+1/2*40
45/4+40/2
11.25+20=31.25 miles is the distance traveled.