1.A bookstore sold 100,000 hardbooks first. Then it sold 200,000 hardbooks and softbooks. The number of the softbooks is 3 times as much as hardbooks which is sold the second time, and the price of a softbook is 1/3 of that of a hardbook. What is the percentage of the sales of softbooks in the total sales. （oldJJ）
【机委】 1/4 ?? 可是我算是(1/3)
2.一个数列，第一个数为3，第二个数是5，第三个是第一个和第二个的积
（就是15），以后任意一个都是其前面所有数的乘积。
现在假设an=t,问a(n＋2)=? (old jj)
【确定】t^4 ?? how
3. In 1997, a company increased M percent of its cost of 1996, and in the same year (1997), the same company increased N percent of profit of 1996( where M>N ), ask the ratio of cost to profit in 1997 increased by how many percent than the ratio of cost to profit in 1996?
【机委】(M-N)/(1+N) ?? 我算是(M-N)/(100+N)??
