A bundle of wires is 150 meters long, 18 meters are used for the first time, and 3 times as much as the first time is used for the second time, how many meters are left?
一捆电线长150米，第一次用去18米，第二次用去的是第一次的3倍，还剩多少米．
<gadget id="calculator">18 * 3</gadget>
<output>54</output>

<gadget id="calculator">150 - 18 - 54</gadget>
<output>78</output>

<result>78</result>