# GMAT Data Sufficiency DiscussionsGMAT & GRE Prep Report

The GMAT and Related Discussions section is very fragmented in terms of the information available at one's disposal. There are one of reply threads and several other redundant threads that have masked the more important ones.
This is an attempt to make the best of explanations, reasonings, qu...
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FIRST SET

1.
option 1 does not give us any clue.
in option 2, either both n,p>0 or both n,p<0..so option2 is also inconclusive.
using both options together,
n>-1 and np>0, we know n is +ve..hence, p shud also be +ve..
hence, option C.

2.
using option1,
12u = 8y+12
hence, y = (12u-12)/8 = /8 in which case, no definite answer
using option2,
x=12z+12 = 12(1+z)...hence, we know FOR SURE the gcd is 12 in this case since 1+z is an integer...thus, answer is B.

3.
i dunno....even i wud hv marked E..

4.
the answer is B because there is only one combination that satisfies the price to be 130.... 23*2+21*4....try all other possible (23cents, 21cents) to see if u get a sum of 130 anywher (0,1), (0,2), (2,2), (4,4)....etc..

Q3 Eqution of any line is x/a + y/b = 1 slope of the line is -b/a .x intercept is a y intercept is b.
Now line l is x/a1+y/b1=1 slope -b1/a1
line k is x/a2+y/b2=1 slope is -b2/a2
product of slopes is (b1 *b2)/ (a1*a2) product of x intercepts is a1*a2 and product of y intercepts is b1*b2
With both statments we can say that product of slope is -ve.