Answer:
The number of adults admitted at the zoo=7
The number of children admitted at the zoo=5
Step-by-step explanation:
a). Determine first expression
Let the number of each group be as follows;
adults=a
children=c
total number of people=12
This can be expressed as;
number of people=number of children+number of adults
replacing;
a+c=12...equation 1
b). Determine the second expression
Let the total cost be expressed as shown;
total cost=(cost per child×number of children)+(cost per adult×number of adults)
where;
total cost=$150
cost per child=$9
number of children=c
cost per adult=$15
number of adults=a
replacing;
(15×a)+(9×c)=150
15 a+9 c=150...equation 2
c). Combine equation 1 and 2 and solve simultaneously
1(15 a+9 c=150)
-
9(a+c=12)=9 a+9 c=108
(15 a-9 a)+(9 c-9 c)=(150=108)
6 a=42
a=42/6
a=7
replacing the value for a in equation 1
7+c=12
c=12-7=5
The number of adults admitted at the zoo=7
The number of children admitted at the zoo=5
