Answer:
15
Step-by-step explanation:
Set the number of children to n.
The number of adults is, thus, n + 25.
The total price of admission is $720, made up of adult tickets and child tickets.
The children paid $8 per child, or
8 * n
The adults paid $15 per adult, or
15 * (n + 25)
These sum of these is equal to the total cost of $720.
8*n + 15*(n + 25) = 720
8n + 15(n + 25) = 720
Multiplying 15 with both n and 25.
8n + 15n + 25*15 = 720
8n + 15n + 375 = 720
Subtracting 375 from both sides.
8n + 15n + 375 - 375 = 720 - 375
8n + 15n = 345
Adding together 8n and 15n.
23n = 345
Dividing both sides by 23.
n = 345/23 = 15
n = 15
As n is the number of children, there are 15 children in the group.
Answer: 15