You're driving a bus that is travelling from Los Angeles to San Francisco.
At the start ,there are 32 passengers on the bus.
At the next bus stop ,11 people get off and nine people get on.
At the next bus stop ,12 people get on and 16 people get off.
At the next bus stop,five people get on and three people get off.
What colour are the bus driver's eyes?
发现这版讨论的问题似乎都挺专业的..一个小的脑筋急转弯