GMAT Prep Problems

Question

The correct answer has been highlighted, so if you looking to practice, please keep in mind that you will see the answer as soon as you read the question. Can some please help me solve these problems. These are questions that I missed. I think these are 700+ level questions. I scored a 49 on the Quant part. Please ignore the second attachment. I made an error when attaching the files. Only look at the first file, which is a word document.

Walker: I deleted second attachment.

chix475ntu · Answer

q1) 
need to find out s=3r+2?? 
st 1) either 3r+2-s =0 or 4r+9-s = 0. not sufficient
st 2) either 4r-6-s=0 or 3r+2-s=0. not sufficient
combining 3r+s-s=0

C

chix475ntu · Answer

2) 
I = 1000 * ( ^n - 1 ). Is r>8??
st 1) I = 210 for n=2
can find r. Sufficient
st 2)  ^2 > 1.15 
approximation
1 + r/100 > 1.1
r/100 > 0.1
==> r% > 0.1 .. interest rate of r is greater than 0.1. Not suficient

A

chix475ntu · Answer

3) 
6 countries, 75 representative - no two countries send same number of representative. country A send second greatest number of representatives, did A sent >=10
st 1) one of the six sent 41
rest 5 sent 34
if A sent 9 or less, the other 4 total would be 25 or more which could be the sum of 4 numbers(8,7,6,4). Not sufficient
st 2) A sent <=12. Not sufficient

combining also we cannot say for sure if country A sent >=10

E

chix475ntu · Answer

4) 
a, n are intergers
a>1, n >1
1*2*3*4*5*6*7*8 = x * a^n
a??

st 1) 
a^n = 64 = 2^6=4^3 = 8^2
Not sufficient

st 2) 
n=6
a has to be 2

B

burnttwinky · Answer

Thanks, but I am still a bit confused on the combining explanation. I see that s= 3r +2 is both 1) and 2), but shouldn't that be sufficient in each statement alone? I feel like i am a bit lost on how to combine these two statements to prove the validity of the initial statement s= 3r + 2.

burnttwinky · Answer

On statement 2 alone, how would you know a=2? by looking at the quation 8! = x * a^6

is it because if you break down 8!, we get 2 x 2 x 2 x 7 x 3 x 2 x 5 x 2 x 2 x 3 x 2 ? There are seven 2's in that, so the x takes care of the remaining 2 x 7 x 5 x 3 x3, etc?

chix475ntu · Answer

Its either or in the case of the above. For ex: take an expression (x-1) * (x-2) = 0. For what value of x does this expression hold good? the values of x are either 1 or 2. To find out the ONLY value of x, we might need another expression say (x-1) * (x-3) = 0. For both the expressions to be true x has to be 1.

HTH

chix475ntu · Answer

you could express the term in many ways such as x * 2^n, y * 3^m etc .. but to have a power of 6, the value of a has to be 2. You cannot express that term with x * 3^6 or y * 4^6 etc.

burnttwinky · Answer

Good explanation. This makes a lot more sense.

silasaaa2 · Answer

1) a^n =64

the possible values are

2^6=64
4^3=64
8^2=64

so insufficient a can be either 2,4,or3

2)n=6

if n is 6 then in 8! should be a multiple of a^6

only a=2 can satisfy this condition so clearly a is 2

so ans is B

jeeteshsingh · Answer

Could you explain this a little more in detail?

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