GRE考试

【单选题】If a is increased by 10% and b is decreased by 10%, the resulting numbers will be equal. What is the ratio of a to b


网考网参考答案：A
网考网解析：
a+10%(a)=a+.1a=1.1a. Also, b -10%(b) = b -.1b = .9b. Then, 1.1a = .9b, and [*] **If after increasing a and decreasing b the results are equal, a must be smaller than b. So, the ratio of a to b must be less than 1. Eliminate Choices C, D, and E. Now, either test Choices A and B or just guess. To test B, pick 2 numbers in the ratio of 9 to 10—90 and 100, for example: 90 increased by 10% is 99. 100 decreased by 10% is 90. They’re not equal. Eliminate Choice B. The answer is Choice A. (110 decreased by 10% is 99.) document.getElementById("warp").style.display="none"; document.getElementById("content").style.display="block"; 查看试题解析出处>>