Xiaochen borrowed the book "One Hundred Thousand Whys (Popular Science Edition)" from the library. If you read 72 pages a day, you can finish it in 15 days. If you read 90 pages a day, you can finish it in a few days less?
小晨同学从图书馆借来《十万个为什么(科普版)》一书，如果每天看72页，15天能看完，如果每天看90页，可以少用几天看完？
<gadget id="calculator">15 / 90</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">72 * (1/6)</gadget>
<output>12</output>

<gadget id="calculator">15 - 12</gadget>
<output>3</output>

<result>3</result>