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