Aunt Li bought 6 kilograms of strawberries for 78 yuan, which is 5 yuan cheaper per kilogram of grapes than per kilogram of strawberries. How much is it per kilogram of grapes?
李大妈买6千克草莓共用去78元，每千克葡萄比每千克草莓便宜5元．每千克葡萄多少元？
<gadget id="calculator">78 / 6</gadget>
<output>13</output>

<gadget id="calculator">13 - 5</gadget>
<output>8</output>

<result>8</result>