Grandpa exercises every morning. It takes 25 minutes to walk around the 750-meter-long circular green belt three times. Please ask for his walking speed.
爷爷每天早锻炼，绕着长750米的环形绿化带走3圈，需要花上25分钟，求爷爷行走的速度．
<gadget id="calculator">3 / 25</gadget>
<output>3/25 = around 0.12</output>

<gadget id="calculator">750 * (3/25)</gadget>
<output>90</output>

<result>90</result>