A watermelon stand sold 46 watermelons. Seventeen customers bought one melon, three customers bought three melons, and the rest bought two melons. How many customers bought two watermelons?
The customers that bought one watermelon bought 1 * 17 = 
<gadget id="calculator">1*17</gadget>
<output>17</output>
17 melons.
The customers that bought three melons bought 3 * 3 = 
<gadget id="calculator">3*3</gadget>
<output>9</output>
9 melons.
The stand sold 46 - 17 - 9 = 
<gadget id="calculator">46-17-9</gadget>
<output>20</output>
20 melons to customers who bought 2 melons.
Thus, 20 / 2 = 
<gadget id="calculator">20/2</gadget>
<output>10</output>
10 customers bought two watermelons.

<result>10</result>