It takes 90 seconds for Xiaopang to go from the first floor to the third floor. At this speed, how many seconds does it take him to go from the second floor to the seventh floor?
小胖从一楼到三楼需要90秒，照这样速度算，他从二楼上到七楼需要多少秒钟．
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">90 / 2</gadget>
<output>45</output>

<gadget id="calculator">7 - 2</gadget>
<output>5</output>

<gadget id="calculator">45 * 5</gadget>
<output>225</output>

<result>225</result>