The ticket price of the water park is: 5 yuan for each individual ticket. If you buy more than 30 tickets at a time, you can get a 20% discount for each ticket. When the number of people is less than 30, at least how many people must go to the water park. Buying 30 tickets will not cost-effective.
水上乐园的票价是：个人票每张5元，一次购票满30张，每张可打八折｡当人数少于30人时，至少要有多少人去水上乐园，买30张票反而合算｡
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">30 / 5</gadget>
<output>6</output>

<gadget id="calculator">5 * (4/5) * 6</gadget>
<output>24</output>

<gadget id="calculator">24 + 1</gadget>
<output>25</output>

<result>25</result>