GMAT Problem Solving Discussions

MBA
983

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

984
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?
. x = y
. y = 1
. x and y are prime integers.
(A) None
(B) only
(C) only
(D) only
(E) and
985

Question is not complete.

986
ashishjha100 Says
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
987
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..
988
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?
. x = y
. y = 1
. x and y are prime integers.
(A) None
(B) only
(C) only
(D) only
(E) and


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...
989

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

990
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 0When, @=45, m= 1
When 45When @ = 135 ( or 45 degrees wrt to -ve X-Axis ) ; m= -1
when 135
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 ...
991
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
992
Hi guys,
-4 (|-20|-5)=
A. 100 B. 60 C. 60 D. 75 E. 100

Acc to me the ans. is C , can someone confirm.....


I think C is correct
993
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 0When, @=45, m= 1
When 45When @ = 135 ( or 45 degrees wrt to -ve X-Axis ) ; m= -1
when 135
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 ...

Bhavin,

Thanks for that description.I remember the All Silver Tea Cups rule ,which says that tan will be
positve only in the 1st and 3rd quadrant. therefore could a slope of -1/10 mean that the angle is in the fourth quadrant?

Raj
994
Bhavin,

Thanks for that description.I remember the All Silver Tea Cups rule ,which says that tan will be
positve only in the 1st and 3rd quadrant. therefore could a slope of -1/10 mean that the angle is in the fourth quadrant?

Raj


position of a line in a particular quadrant not only depend upon the slope, but also its intersecting pts on X & Y Axis..or simply the intercepts..

so, a negative slope does not necessarily mean line passes thru fourth quadrant..
all parallel lines have same slope...so there are infinite line with same slope..and these lines could pass thru any of the 4 quadrants..
but given a slope and one of its intercepts, line becomes fixed..

consider, a line passing thru origin and if its slope is -1/10, it passes thru 2nd and 4th quadrant...now consider all lines parallel to this line, and we can see there are lines in every quadrant...

so, +ve or -ve slope gives u a definite inclination, but not a definite quadrant...
995

A certain club has 20 members. What is the ratio of the member of 5-member
committees that can be formed from the members of the club to the number of 4-member committees that can be formed from the members of the club?
A. 16 to 1
B. 15 to 1
C. 16 to 5
D. 15 to 6
E. 5 to 4

996
A certain club has 20 members. What is the ratio of the member of 5-member
committees that can be formed from the members of the club to the number of 4-member committees that can be formed from the members of the club?
A. 16 to 1
B. 15 to 1
C. 16 to 5
D. 15 to 6
E. 5 to 4



answer to this is (C)..
997
A certain club has 20 members. What is the ratio of the member of 5-member
committees that can be formed from the members of the club to the number of 4-member committees that can be formed from the members of the club?
A. 16 to 1
B. 15 to 1
C. 16 to 5
D. 15 to 6
E. 5 to 4



20C5/20C4= 16/5
answer is C
998
A certain club has 20 members. What is the ratio of the member of 5-member
committees that can be formed from the members of the club to the number of 4-member committees that can be formed from the members of the club?
A. 16 to 1
B. 15 to 1
C. 16 to 5
D. 15 to 6
E. 5 to 4

5 members can be chosen out of 20 members in 20C5 ways
4 members can be chosen out of 20 members in 20C4 ways

Ratio is : 20C5/20C4
= 16/5

hence, answer is C....
999

can anybody help me............

The number of rectangles formed when a family of 8 parallel lines is intersected perpendicularly with another family of 6 parallel lines is

210

280

420

480

540

1000
can anybody help me............

The number of rectangles formed when a family of 8 parallel lines is intersected perpendicularly with another family of 6 parallel lines is

210

280

420

480

540

it will be 7 *5 = 35.
1001
A----------B---------C----------D

Is CD > BC ?
(1) AD = 20
(2) AB = CD

A Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D EACH Statement ALONE is sufficient.
E Statements (1) and (2) TOGETHER are NOT sufficient.

D is the answer..
1002
abchekstylo Says
it will be 7 *5 = 35.

it will be 8C2*6C2=28*15=420