Xiao Pang started from home and went to the library to borrow books at a speed of 75 m/min. After 12 minutes, his father found that he had forgotten his library card, so he immediately ran at a speed of 255 m/min to help him. How many minutes to catch up with Xiaopang?
小胖从家里出发，以75米/分的速度去图书馆借书，12分钟后，爸爸发现他忘带了借书证，就立即以255米/分的速度跑步帮他送去，爸爸用多少分钟追上小胖？
<gadget id="calculator">255 - 75</gadget>
<output>180</output>

<gadget id="calculator">12 / 180</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">75 * (1/15)</gadget>
<output>5</output>

<result>5</result>