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IAMTYRO
08-26-2004, 06:08 AM
Hi, in one of the powerprep problems it wants you to anwswer a question involving parabolas and circles. I thought that sort of math was never on the test! In all of the other pratice tests i have taken in barron's and princeton review they never give problems like that. will i see them on the real GREs?

bigduke
08-27-2004, 03:24 AM
Hi, in one of the powerprep problems it wants you to anwswer a question involving parabolas and circles. I thought that sort of math was never on the test! In all of the other pratice tests i have taken in barron's and princeton review they never give problems like that. will i see them on the real GREs?

Why don't you post the question and we'll let you know if it really requires co-ordinate geometry.

lanpapa
08-28-2004, 10:56 AM
could someone help me with these questions? it appeared in powerprep.

1. which of the following is both the mean and the median of 7 consevutive integers the least of which is x ?

A. x + 4
B. x + 3
C. x + 2
D. (x + 28)/7
E. (x + 3)/2

2. Part of a \$10,000 inheritance was invested at 4% and the remainder was invested at 6%. The total simple annual interest earned on the \$10,000 at the end of one year was \$520.

Column A. The amount invested at 4%
Column B. The amount invested at 6%

1. B
2. B

No.1 I dont really know the exact meaning of the problem. could someone explain it in detail?

No.2 I answered D firstly, because the question dont tell exactly hom many part was invested at 4% and 6%. So i concluded that it was impossible to choose which invested more. Different story if the problem stated ,for example, half of \$10,000 invested at 4\$ and the remainder at 6%, than i would choose B. Could someone check my "thinking"?

bigduke
08-28-2004, 08:20 PM
the first question requires the tactic "substitute vars for numbers", consider x=1 in this case adn then try.

as for the second one ... the value of column B is 6% of 6000. fire up that grey engine now :D

rashmi
08-29-2004, 06:35 AM
For the first question,assume the 7 consecutive no.s are x,x+1,x+2.....x+7,since the question specifies that x is the least .Then add all,the sum comes to be 3x+21. Thus the mean is (7x+21)/7 = x+3.

Also the middle number(median) is {(7+1)/2}nd number which is x+3.

For second question,assume amount invested at 4% is x.
Obviously amount invested at 6% is (10,000-x).
According to question,

{(4/100) * x} + {(6/100) * (10000-x)} = 520.
Solve for x and get the answer.

Hope this helps.

lanpapa
08-29-2004, 07:37 AM
Oooh yes, i got it now!

Thanks rashmi & bigduke for the answer!