Answer: $17.50.
Step-by-step explanation;
If each muffin cost her $0.25 to make and she spent $8.75 making all muffins, then you can divide this amount to find out how many muffins she made (8.75/0.25), this is 35 muffins. If she sold each muffin for $0.50, multiply the number of muffins (35) by their price ($0.50), this is $17.50. Therefore, <em>Maria received $17.50 from selling her muffins</em>.
Multiply both sides by 8. Then divide both sides by 3. Answer is 8/3
First, you multiply $7.50 by 0.2 (20%) to get 1.5. Then, you just add 1.5 to 7.5, and your answer is $9.00.