Last year the price per share of Stock X increased by k percent and the earnings per share of Stock X increased by m percent, where k is greater than m. By what percent did the ratio of price per share to earnings per share increase, in terms of k and m?
~$\frac{k}{m}$~%
(k-m) %
~$\frac{100(k-m)}{100+k}$~%
~$\frac{100(k-m)}{100+m}$~%
~$\frac{100(k-m)}{100+k+m}$~%
By what percent did the [ratio of (price per share to earnings per share) increase], in terms of k and m?
问Ratio 增长的百分比,所以是(新-旧)/旧
把一个数从5/100变成百分号形式表示的话,乘以100。
比率增加的百分比,且100%=1,在进行恒等变形时应注意
A增加了k%,B增加了m%, 求A/B的比率(和先前比)增加了百分之几 为了帮大家理解,设原来A的量为a,B的量为b,原先比率A/B=a/b ①。(胆大的高手其实都直接设1) 后来比率=(1+k%)a/(1+m%)b② 所求值=(②-①)/①即为答案
假定k和m代入,如k=7,m=4,原先分别是100:50时。
求的是比率增加的百分比...这题好绕...
华理陈sir
华理陈sir
这题可以抽象一下,A增加了k%,B增加了m%, 求A/B的比率(和先前比)增加了百分之几 为了帮大家理解,设原来A的量为a,B的量为b,原先比率A/B=a/b ①。(胆大的高手其实都直接设1) 后来比率=(1+k%)a/(1+m%)b② 所求值=(②-①)/①即为答案。