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:

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:

Thus, we get the following system of linear equations:
Equation 1:

Equation 2:

Now, solving for x, the equation 1, we get:
Equation 3:

replacing this into equation 2, we obtain:

now, applying the distributive property, we get:

this is equivalent to:

this is equivalent to:

solving for y, we get:

Now, replacing this data into equation 3, we obtain:

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