Laura is hosting a carwash. She will charge $5 for a car, $6 for a truck, and $7 for an SUV. They raised $100 in total. If they washed 5 SUVs and 5 trucks, how many cars did they wash?
They earned $30 from trucks because 5 x 6 = 
<gadget id="calculator">5*6</gadget>
<output>30</output>
30.
They earned $35 from SUVs because 5 x 7 = 
<gadget id="calculator">5*7</gadget>
<output>35</output>
35.
They earned $35 from cars because 100 - 35 - 30 = 
<gadget id="calculator">100-35-30</gadget>
<output>35</output>
35.
They washed 7 cars because 35 / 5 = 
<gadget id="calculator">35/5</gadget>
<output>7</output>
7.

<result>7</result>