Of the 800 employees in a certain company, 70% have serviced more than 10
years. A number of y of those who have serviced more than 10 years will
retire and no fresh employees join in. When is y if the 10 years employees
become 60% of the total employees?
请问一下我看了网络解答
还不是很清楚
有人可以提示一下吗>__<
感谢!!!