Hi to all, I did the full length GmatTest provided here on gmatclub and found different solutions for these 3 questions... i am not entirely convinced by the OA, which are the ones in bold.
Could u enlighten me ?? (my answers are those in cursive)
Thanks a lot
Riccardo



27. If x and y are positive integers, is x > y?
(1) (x)(x) < y
(2) The square root of x is less than y
(A) statement 1 alone is sufficient to answer the question, but statement 2 alone is not sufficient
(B) statement 2 alone is sufficient to answer the question, but statement 1 alone is not sufficient
(C) both statements together are needed to answer the question, but neither statement alone is sufficient
(D) either statement by itself is sufficient to answer the question
(E) not enough facts are given to answer the question

28. Machine M can produce x units in 3/4 of the time it takes machine N to produce x units. Machine N can produce x units in 2/3 the time it takes machine O to produce x units. If all three machines are working simultaneously, what fraction of the total output is produced by machine N?
(A) 1/2
(B) 1/3
(C) 4/13
(D) 8/29
(E) 6/33

32. Charmaine spent 2/5 of her income in January for rent, and 3/4 of the remainder on other expenses. If she put the remaining $180 in her savings account, how much was her income in January?
(A) $1,000
(B) $1,200
(C) $1,400
(D) $1,600
(E) $1,800

M’s production : 3/4t->1 => t->4/3
N’s production : t->1
O’s production : 3/2t->1 =>t->2/3
If 3 m/c work simultaneously total production in time t -> 1+4/3+2/3 = (3+4+2)/3 = 3
So, N produces 1/3, which is (B)

27) -A

rdg,

For 27, stmt 1 what you are given is X*X < Y, you are taking values to contradict the given condition itself

my reasoning was if X*X, which is always positive, is less than Y then X has to be less than Y. e.g X = - 3 or +3 if Y is greater than X * X which is 9 then both X values are less than Y. So Stmt one is suff.

Stmt 2 however is not suff. take X = 9 and Y = 2
here sqrt X is -3 or +3 one of which is less than Y and other is greater than Y.

28) - B
as rdg exaplained

32) - B
as rdg explained

rdg,
I think you are daling with it incorrectly.

Try reading it like this...
if (X*X) < Y is true then
Can we answer if X > Y?

And answer is YES, WE CAN ANSWER THE QUESTION. although the answer would be NO as X will always be less than Y id (X*X) < Y