In order to celebrate Children's Day, the stationery store held promotional activities. Originally, a pen was 18.5 yuan, but now a pen is 15.8 yuan. The amount of money that can buy two pens in the past can now buy two pens and three pencils. How much is a pencil?
为了庆祝"六一"儿童节，文具店搞促销活动，原来一支钢笔18.5元，现在一支钢笔15.8元．原来能买两支钢笔的钱数，现在能买两支钢笔和3支铅笔，一支铅笔多少钱？
<gadget id="calculator">18.5 * 2</gadget>
<output>37</output>

<gadget id="calculator">15.8 * 2</gadget>
<output>31.6</output>

<gadget id="calculator">37 - 31.6</gadget>
<output>5.4</output>

<gadget id="calculator">5.4 / 3</gadget>
<output>1.8</output>

<result>1.8</result>