Aunt Li bought 4.2 kilograms of apples at 10 yuan per kilogram. Bananas are 0.5 yuan more expensive than apples per kilogram. How many kilograms of bananas can you buy with the same money?
李阿姨买了4.2千克苹果，每千克10元．每千克香蕉比苹果贵0.5元．用同样的钱能买多少千克香蕉？
<gadget id="calculator">10 + 0.5</gadget>
<output>10.5</output>

<gadget id="calculator">4.2 / 10.5</gadget>
<output>0.4</output>

<gadget id="calculator">10 * 0.4</gadget>
<output>4</output>

<result>4</result>