Terry drove along a scenic road using 9 gallons of gasoline. Then Terry went onto the freeway and used 17 gallons of gasoline. Assuming that Terry gets 6.5 miles per gallon better gas mileage on the freeway than on the scenic road, and Terry’s average gas mileage for the entire trip was 30 miles per gallon, find the number of miles Terry drove.
+36915
Hmmmmmm..... average m/g = 30 m/g and g = 26
then 26 g * 30 m/g = 780 miles
Here is the long way:
Looking for miles
30 m/g * (17+9) g = miles total = 17 g * (x+6.5 ) m/g + 9 g * x m/g
30 ( 26) = 17 (x+ 6.5) + 9x
780 = 17x + 110.5 + 9x
780 - 110.5 = 26x
669.5 = 26x
x = 25.75 m/g 17 (25.75 +6.5) + 9(25.75) = 780 m
