posted by Rachel .
The Big Screamer Coaster carries 92 people altogether. Some of its cars carry 4 passengers, and the rest carry 6 passengers. There are three less 6-passenger cars than 4-passenger cars. How many 4-passenger cars are there?
first, represent them as variables:
let x = four-passenger cars
let y = six-passenger cars
set up the equations [since two unknowns, you must have two equations]:
(1) 4x+6y=92 ==> since 92 people altogether
(2) y=x-3 ==> since three less six-passenger cars
then you can substitute the equation (2) to (1):
x=11 four-passenger cars
i hope i was able to help.. =)