Yo solve this question we can use a system of equations. This means we read the question, get 2 facts from it in the form of equations, and make them equal each other to remove one of the variables. It may sound confusing, but here we go.
The park makes $792 in the day. This means that the number of adult ticket prices + child ticket prices = $792. So, we can model this as
1.50x + 4y = 792
Where x is the number of child tickets, and y is the number of adult tickets.
Now, we can also see that x+y = 278 because that’s how many people visited the park.
Since we have 2 equations, we can make them equal each other by rearranging for one of them, let’s do x.
First equation: 792 = 1.5x + 4y
Rearrange for x, x = 528 - (8/3)y
Second equation: 278 = x+y
Rearrange for x, x = 278 - y
Now since we wrote both equations that solve for x, we can make them equal to each other.
528 - (8/3)y = 278 - y
Use algebra to solve for y
y= 150
So, 150 adults. And since 278 people came, 278-150 = 128
x = 128
Answer: D
