Answer:
80
Step-by-step explanation:
Let the number of adults be x
Let the number of children be y
This means that the money paid by adults and kids is $5 multiplied by x (5x) and $2.50 multiplied by y (2.5y)
This will give two equations as shown below
x + y = 240 total admissions......................... equation 1
5x + 2.5y = 800 total money paid..................equation 2
Making x the subject of formula in equation 1
x=240-y......................................................equation 3
Substituting equation 3 into equation 2
5(240-y) + 2.5y = 800 removing the brackets
1200 - 5y + 2.5y = 800 grouping like terms
-5y + 2.5y = 800-1200 simplifying
-2.5y = -400 therefore
-2.5y/-2.5 = -400/-2.5
y = 160
Substituting y into equation 3
x = 240 - y
x = 240 - 160
x = 80
Hence number of adults who attended = 80