Diego can carry 20 pounds of fruit home in his bookbag. If he buys a pound of watermelon, a pound of grapes, and a pound of oranges, how many pounds of apples can he buy?
He is able to carry 3 pounds of watermelon, grapes, and oranges because1+1+ 1 = 
<gadget id="calculator">3</gadget>
<output>3</output>
3.
He can buy 17 pounds of apple because20-3 = 
<gadget id="calculator">20-3</gadget>
<output>17</output>
17.

<result>17</result>