1.There are 8 teams in a certain league and each team play each of the order teams exactly once. If each game is played by 2 teams, what is the total number of gamew played?

2.If mone is invested at r percent interest,compounded annually, the amount of the investment will double in aproximately 70/r years. If Pat's parents invest $5,000 in a long term bond that pays 8 percent interest compounded annually, what will be the approximate total amount of the investment 18 years later, when Pat is ready for college?

第二题答案是$20.000这两题我看不懂题目，谢谢各位XDJM了！

1，一个联盟里有8支队伍，每个队伍都恰好和另外7支分别对抗过1次。如果每场游戏（或比赛）在2支队伍之间进行，一共要进行多少场比赛？

2，如果一笔钱以r的利率投资，按复利计算，在70/r 后总的金额将翻番。按照此公式计算，如果pat的父亲投资债券5000美金，年利率（回报率）为8%，18年后，总额将是多少？

能否share一下书中的解答阿？