Naughty went to the stationery store to buy 5 pens and 8 exercise books for 42 yuan. The price of 1 pen is exactly equivalent to the price of 4 exercise books. What is the price of each pen?
淘气到文具店买5支钢笔和8本练习本共用去42元．1支钢笔的价钱恰好相当于4本练习本的价钱，每支钢笔的价钱是多少元．
<gadget id="calculator">8 * 1</gadget>
<output>8</output>

<gadget id="calculator">5 * 4</gadget>
<output>20</output>

<gadget id="calculator">8 + 20</gadget>
<output>28</output>

<gadget id="calculator">42 / 28</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">(3/2) * 4</gadget>
<output>6</output>

<result>6</result>