Answer:
26 children
Explanation:
Step 1 Create a system of equations
Firstly, we know that it cost $1.50 for children and $4 for adults and we know that 505$ is the total amount collected
So if x = number of children and y = number of adults
Then 1.50x + 4x = 505
We also know that 220 total people entered which consists of adults and children.
Again, if x = number of children and y = number of adults
Then we can say that x + y = 220
So we now have the two equations
1.50x + 4y = 505 and x + y = 220
Step 2 Solve the equation
There are many methods you can use to solve this equation however I'd recommend the substitution method as we can easily solve for x or y in the equation x + y = 220 and isolate one of the variables, we can then easily substitute that into the other equation.
Isolating y
x + y = 220
==> subtract x from both sides
y = 220 - x
We now substitute y into the other equation and solve for x(# of children)
1.5x + 4y = 505
==> plug in y = 220 - x
1.5x + 4(220 - x) = 505
==> distribute 4
1.5x + 440 - 4x = 505
==> combine like terms
-2.5x + 440 = 505
==> subtract 440 from both sides
-2.5x = -65
==> divide both sides by -2.5
x = 26
So 26 children attended the fair that day.