GMAT Problem Solving Discussions

[ashishjha100]

Originally Posted by bhavin422

yes...ans is A...
3x/y is a prime integer greater than 2..so x/y need not be an integer...and also x need not be equal to be y, it is also not necessary for x and y to be prime integers...Hence A..

If in doubt, just consider, x=15 and y = 9...then 3x/y is prime (5) and x not equal to y..
there are many more egs..

Thanks buddy.........for ur speedy help.

[harneet.m.kaur]

Can some one help with this problem ?


The dimensions of a rectangular box - 2, 8, 20 inches is to be completely wrapped with paper. If a single sheet of paper is to be used without patching, then the dimensions of the paper could be
(A) 17 in by 25 in
(B) 21 in by 24 in
(C) 24 in by 12 in
(D) 24 in by 14 in
(E) 26 in by 14 in

[harneet.m.kaur]

Can someone pls help me with this problem ?
If y ≠ 3 and is a prime integer greater than 2, which of the following must be true?
Ⅰ. x = y
Ⅱ. y = 1
Ⅲ. x and y are prime integers.
(A) None
(B) Ⅰ only
(C) Ⅱonly
(D) Ⅲonly
(E) Ⅰand Ⅲ

[ashishjha100]

Question is not complete.

[harneet.m.kaur]

Originally Posted by ashishjha100

Question is not complete.

Ashish,

These Qs are picked up from the GMAT practice problems. In what sense do you say that the problems are incomplete

Thanks,
H

[bhavin422]

Originally Posted by harneet.m.kaur

Can some one help with this problem ?


The dimensions of a rectangular box - 2, 8, 20 inches is to be completely wrapped with paper. If a single sheet of paper is to be used without patching, then the dimensions of the paper could be
(A) 17 in by 25 in
(B) 21 in by 24 in
(C) 24 in by 12 in
(D) 24 in by 14 in
(E) 26 in by 14 in

total surface area of box should be lesser than area of paper...

Total surface area of box = 2 (2*8 + 2*20 + 8*20) = 432

Only 21*24 = 504 > 432..
Hence B..

[bhavin422]

Originally Posted by harneet.m.kaur

Can someone pls help me with this problem ?
If y ≠ 3 and is a prime integer greater than 2, which of the following must be true?
Ⅰ. x = y
Ⅱ. y = 1
Ⅲ. x and y are prime integers.
(A) None
(B) Ⅰ only
(C) Ⅱonly
(D) Ⅲonly
(E) Ⅰand Ⅲ

this question is incomplete because you have forgot to type the equation that is greater than 2..may be it cud be smtng like 3x/y is a prime integer greater than 3..

then it is similar to the question posted above and solution is also given...

if not..give the exact sum...

[krajkumar6]

hi,

What does it mean when we know that the slope of a line is -1/10 or(a negative value)?
I want to know what we can gather from that information.

Raj

[bhavin422]

Originally Posted by krajkumar6

hi,

What does it mean when we know that the slope of a line is -1/10 or(a negative value)?
I want to know what we can gather from that information.

Raj

hi raj,
slant of the line can be very much understood by its slope...
we know, slope = m = tan @ = (y2-y1)/(x2-x1)...
Let @ be the inclination of line in degrees wrt. Positive X- Axis...

Then :
1) When @ is acute, slope is positive
2) and when @ is obtuse, slope is negative...( or acute inclination of line wrt to negative X-Axis )
3) when line is parallel to X - Axis slope is zero
4) When line is parallel to Y-Axis slope is not defined..

To put things in perspective, slope is dependent on inlination @ wrt to +ve X-Axis .
When 0<@<45 : 0<m<1
When, @=45, m= 1
When 45<@<90 ; 1<m<tending to infinity
when @ = 90 ; slope = not defined
when 90<@<135 ; -tending to infinity <m < -1
When @ = 135 ( or 45 degrees wrt to -ve X-Axis ) ; m= -1
when 135< @< 180 ; -1<m<0...

this takes care of entire range of angles from 0 to 180 and its corresponding slope...

so, slope of -1/10 implies, line makes an obtuse angle wrt to X axis or it is inclined towards -ve X axis such that for evry 1 unit change in Y axis there is 10 units change in X axis..
Simply ,line can be considered to be passing thru pts A (0,1) and B(10, 0)..
not necessarily just thru these 2 pts...this is just to give an eg..

hope this clears your doubt ...

[gaurav_846]

Originally Posted by harneet.m.kaur

Can some one help with this problem ?


The dimensions of a rectangular box - 2, 8, 20 inches is to be completely wrapped with paper. If a single sheet of paper is to be used without patching, then the dimensions of the paper could be
(A) 17 in by 25 in
(B) 21 in by 24 in
(C) 24 in by 12 in
(D) 24 in by 14 in
(E) 26 in by 14 in

I think the answer is B. By process of elimination you can remove all the options as the total surface area (432) is covered only by B