Answer:
To find out how much Tina earned babysitting, you can set up the equation based on the information given:
Let \( x \) be the amount Tina earned babysitting. According to the problem, $20 is 80% of her earnings:
\[
0.80 \times x = 20
\]
To solve for \( x \), divide both sides of the equation by 0.80:
\[
x = \fraction {20}{0.80}
\]
\[
x = 25
\]
So, Tina earned **$25** babysitting.
