大全-Math-DS-section 17-20

大全-Math-DS-section 17-20

20. Is less than 1,000 ?

(1) 5^(k-1) >3000

(2)  5^(k-1) >5^k - 500

ans: B.

I thought it should be D because 1) gives us : 5^k >3000*5, thus 5^(k-1) >15000

NN, please help, thanks.

i am sorry, should be:

大全-Math-DS-section 17-20

20. Is 5^k ATH connecttype="rect" gradientshapeok="t" extrusionok="f">ATH>less than 1,000 ?

(1) 5^(k-1) >3000

(2)  5^(k-1) >5^k - 500

ans: B.

I thought it should be D because 1) gives us : 5^k >3000*5, thus 5^k >15000

NN, please help, thanks.

不好意思啊~~题目highlight处好像不全啊...什么<1000呢？

THAT SHOULD BE 5^k WHICH WAS CORRECTED IN SECOND FLOOR.

happyfish0517, PLEASE HELP, THANK YOU VERY MUCH.

UP AGAIN:

大全-Math-DS-section 17-20

20. Is 5^k ATH gradientshapeok="t" extrusionok="f" connecttype="rect">ATH>less than 1,000 ?

(1) 5^(k-1) >3000

(2)  5^(k-1) >5^k - 500

ans: B.

I thought it should be D because 1) gives us : 5^k >3000*5, thus 5^k >15000

NN, CORRECT ME, thanks.

SORRY啊，才来~~

如果正如LZ所述，这题是应该选D...

如果1）中是5^(K-1)<3000，那就是B...

汗！

另外...我弱弱的问一下楼主~~~数学大全是什么？

是CD上下载的吗？为什么我没找到过？？

谢谢！~