题目信息
An investment has been growing at a fixed annual rate of 20% since it was first made; no portion of the investment has been withdrawn, and all interest has been reinvested. How much is the investment now worth?
A:Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B:Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C:BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D:EACH statement ALONE is sufficient.
E:Statements (1) and (2) TOGETHER are NOT sufficient.
参考答案及共享解析
共享解析来源为网络权威资源、GMAT高分考生等； 如有疑问，欢迎在评论区提问与讨论
本题耗时：
已选答案：
正确答案：
B:Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
Algebra Applied problems
If the investment was initially worth $P, then after one year the investment was worth $1.2P, after two years the investment was worth 1.2($1.2P) = $1.44P, after three years the investment was worth 1.2($1.44P) = $1.728P, etc.
Given that the investment was worth $(P + 0.44P) = $1.44P, it follows from the remarks above that the investment was first made two years ago. However, nothing is known about the value of P; NOT sufficient. Let $X be how much the investment was worth one year ago. Then the investment is now worth $1.2X. However, if $600 had been withdrawn from the investment one year ago, then the investment would have been worth $(X − 600) one year ago and the investment would have been worth $1.2(X − 600) = $(1.2X − 720) today. It is given that this amount, namely $(1.2X − 720), is 12 percent less than $1.2X. Therefore, 1.2X − 720 = (0.88)(1.2X). This equation can be solved for X, and using this value of X, the value of 1.2X can be determined; SUFFICIENT.
The correct answer is B;statement 2 alone is sufficient.
If the investment was initially worth $P, then after one year the investment was worth $1.2P, after two years the investment was worth 1.2($1.2P) = $1.44P, after three years the investment was worth 1.2($1.44P) = $1.728P, etc.
Given that the investment was worth $(P + 0.44P) = $1.44P, it follows from the remarks above that the investment was first made two years ago. However, nothing is known about the value of P; NOT sufficient. Let $X be how much the investment was worth one year ago. Then the investment is now worth $1.2X. However, if $600 had been withdrawn from the investment one year ago, then the investment would have been worth $(X − 600) one year ago and the investment would have been worth $1.2(X − 600) = $(1.2X − 720) today. It is given that this amount, namely $(1.2X − 720), is 12 percent less than $1.2X. Therefore, 1.2X − 720 = (0.88)(1.2X). This equation can be solved for X, and using this value of X, the value of 1.2X can be determined; SUFFICIENT.
The correct answer is B;statement 2 alone is sufficient.
加入收藏
在线答疑
题目来源
