A math teacher had $100 to buy three different types of calculators. A basic calculator costs $8. A scientific calculator costs twice the price as the basic while a graphing calculator costs thrice the price as the scientific. How much change did she receive after buying those three different types of calculators?
Thoughts? Step-by-step reasoning:
A scientific calculator costs $8 x 2 = $16. A graphing calculator costs $16 x 3 = $48. So, she spent $8 + $16 + $48 = $72 for the three calculators. Therefore, the math teacher received $100 - $72 = $28 change.
Thus, the answer is 28.