The price of buying 2 pairs of triangle rulers is equivalent to the price of buying 4 rulers. I bought 3 pairs of triangle rulers and 6 rulers. The total cost is 24 yuan. How much is a ruler?
买2副三角尺的价钱相当于买4把直尺的价格，我买了3副三角尺和6把直尺，总共用去24元，直尺多少钱一把？
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 * 3</gadget>
<output>6</output>

<gadget id="calculator">6 + 6</gadget>
<output>12</output>

<gadget id="calculator">24 / 12</gadget>
<output>2</output>

<result>2</result>