Uncle Zhang bought 2 kilograms of walnuts and 3 kilograms of cake. He paid 100 yuan and got back 50.5 yuan. The walnuts were 16.5 yuan per kilogram. How much is the cake per kilogram?
张伯伯买了2千克核桃和3千克蛋糕，付出100元，找回50.5元，核桃每千克16.5元，蛋糕每千克多少元？
<gadget id="calculator">16.5 * 2</gadget>
<output>33</output>

<gadget id="calculator">100 - 50.5 - 33</gadget>
<output>16.5</output>

<gadget id="calculator">16.5 / 3</gadget>
<output>5.5</output>

<result>5.5</result>