Bamboo grows about 4 cm per hour during the vigorous growth period, and the bell-shaped fungus grows faster, about 25 cm per hour during the vigorous growth period. If they are all in the vigorous growth period, the height of the bamboo is 32 cm at the beginning, and the height of the bell fungus is 0.5 cm. How long can the height of the bell fungus catch up with the bamboo?
竹子在生长旺盛期每时约增高4厘米，钟状菌生长更快，生长旺盛期每时约增高25厘米．如果它们都在生长旺盛期，开始时竹子高32厘米，钟状菌高0.5厘米，几时后钟状菌的高度可赶上竹子？
<gadget id="calculator">32 - 0.5</gadget>
<output>31.5</output>

<gadget id="calculator">25 - 4</gadget>
<output>21</output>

<gadget id="calculator">31.5 / 21</gadget>
<output>1.5</output>

<result>1.5</result>