A worker processes a batch of products, and he gets paid 0.75 yuan for each genuine product he processes. A fine of 1.50 yuan will be imposed for each defective product processed. On this day, the genuine products he processed were 7 times the defective ones, and he earned 11.25 yuan. So how many defective products did he process that day?
一个工人加工一批产品，他每加工出一件正品，得报酬0.75元．每加工出一件次品，罚款1.50元．这天他加工的正品是次品的7倍，得款11.25元．那么他这天加工出多少件次品．
<gadget id="calculator">0.75 * 7</gadget>
<output>5.25</output>

<gadget id="calculator">5.25 - 1.5</gadget>
<output>3.75</output>

<gadget id="calculator">11.25 / 3.75</gadget>
<output>3</output>

<result>3</result>