你见过什么样的聪明人

What's the smartest thing you've ever seen someone do?
你见过别人做什么最聪明的事？

获得32.8k好评的回答@Anurag Chaudhary：

When I was in the Gandhinagar office of TCS, a juice seller (20 something) at the cafeteria used this amazing hack for increasing his sales.
我在交通管制站的甘地纳格尔办事处时，自助餐厅里一个卖果汁的人用这一妙招来提高销售量。

So, during the peak hours, he found it difficult to manage since he didn’t have any help on his counter. The employees would rush to him with their coupons for bournvita, cold coffee, mixed juice, shakes and everything else, all at once. With only two mixers and two human hands, he had his limitations and often the customer would have to wait for half an hour or more. He didn’t even have a refrigerator.
所以在就餐高峰期他发现应付不过来，因为前台没人帮忙，店员们拿着吉百利、冰咖啡、混合果汁、奶昔等各种优惠券一起来找他。店里只有两个搅拌机，他只有两只手，条件有限，顾客经常至少要等半小时，他甚至连冰箱都没有。

I would look at him for days and would feel pity at him. Then, a month later, I noticed a change at his counter. The customers were still aplenty but instead of half an hour, they were getting their orders in 10 minutes.
我观察了他几天，很同情他。可是一个月之后，我注意到他的柜台发生了变化，顾客仍然很多，但他们不用再等半小时了，10分钟就能拿到饮品。

So what he did was, he had made an estimate of what kind of drinks most people have at his counter. He had decorated an entire row of plastic glasses with bournvita in it, waiting for the hot milk to be poured. Something similar was done for oreo shake and cold coffee too. So, he was saving time on tearing packets and peeling off fruits and spooning out bournvita and sugar into the glasses. By the time he juiced fruits for one order, he had already supplied 5 glasses of bournvita and so on. I also noticed that he had worked on his hand eye coordination and speed. He was mixing things fast and had replaced glasses with plastic glasses and cups. Instead of keeping it in the corner, he kept the trash bucket, near his feet. He stood at one place and did 5 different things.
他是怎么做到的？他估算了一下大部分人在他那儿会点哪种饮品，他在一整排塑料杯里放好吉百利，只等着加热牛奶就搞定了，他也准备了奥利奥奶昔和冰咖啡。这样就能省下时间去撕包装、剥水果皮、舀出吉百利、往杯里加糖。他榨一份果汁的时间都能卖出5杯吉百利了。我还注意到他训练了手眼协调能力和速度。他混合东西速度很快，把玻璃杯换成了塑料杯和小杯子。他把垃圾桶从角落里挪到了脚边上，他站在一个地方同时能做5件事。

He told me he never went to school after class 4th because he hated mathematics, but he so efficiently understood and applied the demand supply curve for his profit.
他跟我说4年级以后就辍学了，因为他讨厌数学，但却把供求曲线弄得如此明白并用来赚钱。