It cost 46.2 yuan to buy 5.5 catties of cheese cake, and 29.9 yuan to buy 4.6 catties of chocolate cake. Then, how much is the difference between the unit price of cheese cake and chocolate cake?
买5.5斤芝士蛋糕花了46.2元，4.6斤巧克力蛋糕花了29.9元，那么，芝士蛋糕与巧克力蛋糕的单价相差多少元/斤
<gadget id="calculator">46.2 / 5.5</gadget>
<output>8.4</output>

<gadget id="calculator">29.9 / 4.6</gadget>
<output>6.5</output>

<gadget id="calculator">8.4 - 6.5</gadget>
<output>1.9</output>

<result>1.9</result>