The school bought 4 pairs of badminton rackets and 20 skipping ropes, paid 150 yuan, and got back 11.4 yuan. Each pair of badminton rackets is 18.4 yuan, how much is each skipping rope?
学校买4副羽毛球拍和20根跳绳，付出150元，找回11.4元．每副羽毛球拍18.4元，每根跳绳多少元？
<gadget id="calculator">4 * 18.4</gadget>
<output>73.6</output>

<gadget id="calculator">150 - 11.4 - 73.6</gadget>
<output>65</output>

<gadget id="calculator">65 / 20</gadget>
<output>13/4 = around 3.25</output>

<result>13/4 = around 3.25</result>