My mother buys 1 bag of rice and 3 kg of sugar in the supermarket for a total of 42 yuan. It is known that the price of this bag of rice is 27 yuan, how much is it per kilogram of white sugar?
妈妈在超市买1袋大米和3千克白糖一共用去42元．已知这袋大米的价钱是27元，每千克白糖多少元？
<gadget id="calculator">42 - 27</gadget>
<output>15</output>

<gadget id="calculator">15 / 3</gadget>
<output>5</output>

<result>5</result>