Xiaohong’s mother buys a pair of trousers for 87 yuan, and the price of a jacket is three times that of a pair of trousers. How much does it cost to buy a pair of trousers?
小红妈妈买一条裤子87元，一件上衣的价钱是一条裤子的3倍，买一套需多少钱？
<gadget id="calculator">87 * 3</gadget>
<output>261</output>

<gadget id="calculator">261 + 87</gadget>
<output>348</output>

<result>348</result>