Manage volume units later. First, analyze and solve the main problem.
This is a fuel efficiency uniform rates problem
RATE VOLUME DISTANCE
km/L Liters Kilometers
CITY C 8.9 100
HWY H 7.2 100
Find rates, C and H.
and
How much fuel used, first as liters, for 50 km "into" the city and 250 km on highway? (Assuming the combination, addition).
R*V=D rate volume distance
V=D/R to find volume
, in LITERS
, LITERS
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3.7854 Liters is 1 US Gallon.