Ms. Jones got thank you cards from 30% of her class. 1/3 of these contained a gift card for $10. If she got $50 in gift cards, how many students were in her class?
She got 5 gift cards because 50 / 10 = 
<gadget id="calculator">50/10</gadget>
<output>5</output>
5.
She got 15 thank you cards because 5 / (1/3) = 
<gadget id="calculator">5/(1/3)</gadget>
<output>15</output>
15.
She has 50 students because 15 / .3 = 
<gadget id="calculator">15/.3</gadget>
<output>50</output>
50.

<result>50</result>