Solution:
Let us denote by x the number of child tickets sold and by y the number of adult tickets sold. According to the problem, we have that 137 tickets were sold, then we get the following equation:
Equation 1:
[tex]x+y\text{ = 137}[/tex]On the other hand, according to the problem, child admission is $5.80 and adult admission is $9.70 and the total sales were S1094.90.
Thus, we get the following equation:
Equation 2:
[tex]5.80x\text{ + 9.70y = }1094.90[/tex]Thus, we get the following system of linear equations:
Equation 1:
[tex]x+y\text{ = 137}[/tex]Equation 2:
[tex]5.80x\text{ + 9.70y = }1094.90[/tex]Now, solving for x, the equation 1, we get:
Equation 3:
[tex]x=\text{ 137-y}[/tex]replacing this into equation 2, we obtain:
[tex]5.80(137-y)\text{ + 9.70y = }1094.90[/tex]now, applying the distributive property, we get:
[tex]794.6-5.80y\text{ + 9.70y = }1094.90[/tex]this is equivalent to:
[tex]-5.80y\text{ + 9.70y = }1094.90-794.6[/tex]this is equivalent to:
[tex]3.90y=300.3[/tex]solving for y, we get:
[tex]y=\frac{300.3}{3.90}=77[/tex]Now, replacing this data into equation 3, we obtain:
[tex]x=\text{ 137-y}=137-77=60[/tex]So that, we can conclude that the correct answer is:
the number of child tickets sold = x = 60
the number of adult tickets sold = y = 77