A bundle of wires is 150 meters long, 18 meters are used for the first time, and 3 times the length of the first time is used for the second time, how many meters is the bundle of wires shorter than the original one?
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，这时这捆电线比原来短了多少米．
<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<gadget id="calculator">18 * 4</gadget>
<output>72</output>

<result>72</result>