In this question,We have to group the given expression to get 5 as the final answer .

Here we put 5 +20 in parenthesis, that is

And we do the required operations, that is

And we get 5.
Answer:
3) 9.2ml
4) .25ml
Have to have 20 characters
<span>x = child ticket price
y = adult ticket price
5x+3y=52 the cost accounting for the first group.
3x+2y=38 the cost accounting for the second group.
Child price: 5$
Adult price: 9$</span>
The answer is 34 cents per cup, (0.34)