Zhang Wei bought 100 balls, 28% of which are red balls. The ratio of red balls to basketballs is 4:5. How many basketballs are there?
张伟买了100个球，其中红球占28%，红球与篮球的比是4：5，篮球有多少个？
<gadget id="calculator">28 / 100</gadget>
<output>7/25 = around 0.28</output>

<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(7/25) / (4/5)</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">100 * (7/20)</gadget>
<output>35</output>

<result>35</result>