The admission fee at a local zoo is
$2.50 for children and $5.50 for adults. On a certain day, 1800 people entered the zoo and $6,300.00 was collected. How many children and how many adults entered the zoo?
Let c = the number of children entering the zoo, and a = the number of adults entering the zoo.
c + a = 1800 ... 2.5 c + 2.5 a = 4500
2.5 c + 5.5 a = 6300
subtracting equations (to eliminate c) ... 3 a = 1800
solve for a , then substitute back to find c