The price per share of stock x increased by 10 percent over the same time period that the price per share of stock y decreased by 10 percent.The reduced price per share of stock y was what percent of the original price per share of stock x?
1)The increased price per share of stock x was equal to the original price per share of stock y.
2)The increase in the price per share of stock x was 10/11.

key: D (EACH Statement ALONE is suffient.)
my choice: A(Statement (1)ALONE is sufficient,but Statement(2) is ALONE is not suffient.)

两个被选同样是给出了x和y的关系，所以都对

you can know both value of x and y through first data
but you can only find out the value of x in the second one
so the first one is sufficient, the second one is not

2)The increase in the price per share of stock x was 10/11.只知道X的情况，肯定推不出答案来。