A bottle of cough syrup is 30ml in total. Xiao Ming can only drink (5/2)ml each time, 3 times a day. How many days can this bottle of syrup last?
一瓶止咳糖浆共30毫升，小明每次只能喝(5/2)毫升，每天喝3次，这瓶糖浆可以喝几天？
<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">(5/2) * 3</gadget>
<output>15/2 = around 7.5</output>

<gadget id="calculator">30 / (15/2)</gadget>
<output>4</output>

<result>4</result>