Two motorboats, A and B, set out from the east and west ports which are 324 kilometers apart at the same time, and meet each other in 3 hours. It is known that the speed of the speedboat A is 53.5 kilometers per hour, how many kilometers per hour is the speed of the speedboat B?
甲、乙两艘汽艇同时从相距324千米的东西两港相对开出，3小时相遇，已知甲汽艇每小时行53.5千米，乙汽艇每小时行多少千米？
<gadget id="calculator">324 / 3</gadget>
<output>108</output>

<gadget id="calculator">108 - 53.5</gadget>
<output>54.5</output>

<result>54.5</result>