Two naughty children walk in the opposite direction of the escalator. The boy can walk 3 steps per second, and the girl can walk 2 steps per second. From one end of the escalator to the other end, the boy takes 100 seconds and the girl walks 300 seconds Second. Q: How many steps does the escalator have?
两个顽皮的孩子逆着自动扶梯行驶的方向行走，男孩每秒可走3级梯级，女孩每秒可走2级梯级，结果从扶梯的一端到达另一端男孩走了100秒，女孩走了300秒．问：该扶梯共有几级梯级？
<gadget id="calculator">300 * 2</gadget>
<output>600</output>

<gadget id="calculator">3 * 100</gadget>
<output>300</output>

<gadget id="calculator">600 - 300</gadget>
<output>300</output>

<gadget id="calculator">300 - 100</gadget>
<output>200</output>

<gadget id="calculator">300 / 200</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">100 * (3/2)</gadget>
<output>150</output>

<gadget id="calculator">300 - 150</gadget>
<output>150</output>

<result>150</result>