Answer:
15
Step-by-step explanation:
Let the number of adult tickets be x while children ticket be y. Since the total tickets were 20 then we can form the equation
x+y=20
Making x the subject then x=20-y
Considering the cost of each ticket
15x+10y=225
Substituting x with 20-y then
15(20-y)+10y=225
300-15y+10y=225
Collecting like terms
300-225=15y-10y
75=5y
Y=75/5=15
To find x, we already know that x=20-y hence x=20-15=5
Therefore, children tickets are 15 while adult tickets are 5.
The question only needs us to know the children tickets, y which is 15