The ratio of the walking speed of A and B is 4:3. From point A to point B, A needs to walk for 15 minutes, how many minutes does B need to walk?
甲乙两人的步行速度之比是4：3，从A地到B地，甲要走15分钟，乙要走多少分钟？
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">15 / (3/4)</gadget>
<output>20</output>

<result>20</result>