Problema Solution
The number of miles per gallon of gasoline that a vehicle averages varies inversely as the average speed the car travels. A vehicle get 25 mpg at 68 mph. how many miles per gallon will it get at 78 mph?
Answer provided by our tutors
let
m = mpg of gasoline that a vehicle averages
v = the average speed of the car
m = k*(1/v)
where k is constant
for v = 68 mph we have m = 25 mph
25 = k(1/68)
k = 25*68
k = 1700
the formula now is
m = 1700*(1/v)
if v = 78 for m we have
m = 1700(1/78)
m = 21.79 mpg