Kobayashi goes from home to school, and walks at a speed of 60 m/min. It took 15 minutes to go to school, which was 3 minutes less than after school. What is the walking speed of Kobayashi after school?
小林从家去学校，上学时步行的速度是60米/分．上学时用了15分钟，比放学少用了3分钟．放学时小林步行的速度是多少？
<gadget id="calculator">15 + 3</gadget>
<output>18</output>

<gadget id="calculator">15 / 18</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">60 * (5/6)</gadget>
<output>50</output>

<result>50</result>