Real world math

Question

At the city museum, child admission is $5.10 and adult admission is $8.60. On Thursday, four times as many adult tickets as child tickets were sold, for a total sales of $1145.50. How many child tickets were sold that day?

Answer 1

5.10x+8.60*4x=1145.5

5.10x+34.40x=1145.5

39.50x=1145.5

x=29 children

Answer 2

We define our variables as:

a = number of adult tickets sold

c = number of children tickets sold

Thus the formula for money made would be

5.10c + 8.60a = 1114.50

We can solve for both variables at the same time we must write one variable in terms of the other.

Since 4 times as many adult tickets were sold then children tickets, we can right c in terms of a as:

4c = a

We can then subsitute (make sure to use parenthesis when substituting):

5.10c + 8.60(4c) = 1145.50

After multiplying we get:

5.10c + 34.40c = 1145.50

We add like terms:

39.50c = 1145.50

We divide to solve for c:

c = 29

And since adult tickets were 4 times more:

a = 116.