In Disneyland, the imprudent Mickey Mouse and Donald Duck drove the train face to face on the same railroad track. The speed of Mickey Mouse was 10 meters per second, and the speed of Donald Duck was 8 meters per second. Because they did not brake in time, the two small trains collided. If Mickey Mouse and Donald Duck brake at the same time a few seconds before the collision, not only can the collision be avoided, but the distance between the fronts of the two cars can also be kept 3 meters. (The little trains of Mickey Mouse and Donald Duck slide forward 30 meters after the emergency brake)
迪斯尼乐园里，冒失的米老鼠和唐老鸭把小火车面对面地开上同一条铁轨，米老鼠的速度是每秒10米，唐老鸭的速度是每秒8米．由于没有及时刹车，结果两列小火车相撞．假如米老鼠和唐老鸭在相撞前多少秒同时紧急刹车，不仅可以避免两车相撞，两车车头还能保持3米的距离．(紧急刹车后米老鼠和唐老鸭的小火车分别向前滑行30米)
<gadget id="calculator">30 * 2</gadget>
<output>60</output>

<gadget id="calculator">60 + 3</gadget>
<output>63</output>

<gadget id="calculator">10 + 8</gadget>
<output>18</output>

<gadget id="calculator">63 / 18</gadget>
<output>7/2 = around 3.5</output>

<result>7/2 = around 3.5</result>