Mr. Li bought 5 volleyballs for 175 yuan, and he wants to buy 15 more of the same volleyballs. How much more yuan do he need to prepare?
李老师买5个排球花了175元，他还想再买15个同样的排球，需要再准备多少元？
<gadget id="calculator">175 / 5</gadget>
<output>35</output>

<gadget id="calculator">35 * 15</gadget>
<output>525</output>

<result>525</result>