拜托各位了！这两道数学题，哼哼~~

1,if money is invested at r percent interest,com-pounded annually,the amount of the investment will double in approximately 70/r years,if Pats parents invested $5,000 in a long term bond that pays 8 percent interest,compounded annually,what will be the approximate total amount of the investment 18years later,when Pat is ready for college?

答案是$20，000

2，a bar over a sequence of digits in a decimal indicates that the sequence repeats indefinitely.what is the value of (10^4-10^2)(0.0012)      （注：0.0012中的12上面有条横杠，我不会打）

答案是12      最好帮我翻译一下，根本没看懂

第一题 ：存入的钱每隔70/r 就翻一倍，利息8%时也就是每隔70/8=8.75年翻一倍，那么18年就是要翻两番咯。。所以就是 5000*4=20000

第二题：这个是小学题目，就是考无限循环小数，循环小数位上面有条bar记得吧？就是那个。那就好办了。 0.12(bar)=0.0012121212……

(10^4-10^2)(0.0012)=12.121212……-0.121212……=12

真的非常感谢，我以为没人答了呢~~感动ING~~