Mary goes with her 3 children to the circus. Tickets cost $2 for adults and $1 for children. Mary pays with a $20 bill. How much change will she receive?
Mary's ticket costs $2/ticket * 1 ticket = $
<gadget id="calculator">2*1</gadget>
<output>2</output>
2.
Mary's children's tickets cost 3 tickets * $1 = $
<gadget id="calculator">3*1</gadget>
<output>3</output>
3.
Together the tickets cost $2 + $3 = $
<gadget id="calculator">2+3</gadget>
<output>5</output>
5.
After paying with a 20-dollar bill, Mary will receive $20 - $5 = $
<gadget id="calculator">20-5</gadget>
<output>15</output>
15.

<result>15</result>