GMAT Data Sufficiency Discussions

1. If x > 0, is x/y > x ?
(1) 0 y
(2) x > 1



Take 1 - y
1
x
Sufficient

2 doesnot say anything about y & Insuff.

Ans A
1. If x > 0, is x/y > x ?
(1) 0 y
(2) x > 1


X/y>x implies is yfrom option 1 its clear tht y lies between 0 and 1. so the question can be answered.

so only A is sufficient.

whts OA?
X/y>x implies is yfrom option 1 its clear tht y lies between 0 and 1. so the question can be answered.

so only A is sufficient.

whts OA?


OA is A...
1. How many of the 60 cars sold last month by a certain dealer had neither power windows nor a stereo?
(1) Of the 60 cars sold, 20 had a stereo but not power windows.
(2) Of the 60 cars sold, 30 had both power windows and a stereo.
2. In the xy-plane, does the point (4, 12) lie on line k ?
(1) The point (1, 7) lies on line k.
(2) The point (-2, 2) lies on line k.
1. In the rectangular coordinate system, are the points (r, s) and (u, v) equidistant from the origin ?
(1) r + s = 1
(2) u = 1 r and v = 1 s
2. Is ab = 1 ?
(1) aba = a
(2) bab = b
1. How many of the 60 cars sold last month by a certain dealer had neither power windows nor a stereo?
(1) Of the 60 cars sold, 20 had a stereo but not power windows.
(2) Of the 60 cars sold, 30 had both power windows and a stereo.
2. In the xy-plane, does the point (4, 12) lie on line k ?
(1) The point (1, 7) lies on line k.
(2) The point (-2, 2) lies on line k.

Q1. E, No info on cars with power window and no stereo.
Q.2 C, Using 1 & 2 slope & y-intercept could be determined and could be verified using (4,12) as one end point.
1. In the rectangular coordinate system, are the points (r, s) and (u, v) equidistant from the origin ?
(1) r + s = 1
(2) u = 1 r and v = 1 s
2. Is ab = 1 ?
(1) aba = a
(2) bab = b

Q1. C. The distance from origin is given by sqrt(x^2 + y^2) and sqrt(u^2 + v^2), using eq2 and substituting for u and v; sqrt((1-r)^2 + (1-s)^2) and solving further gives sqrt(2-2(r+s) + r^2 + s^2).
Using eq1 and substituting for r+s=1 makes two eq same.
2. Is ab = 1 ?
(1) aba = a
(2) bab = b

Q.2 Each statement alone is sufficient. Ans is D
1. How many of the 60 cars sold last month by a certain dealer had neither power windows nor a stereo?
(1) Of the 60 cars sold, 20 had a stereo but not power windows.
(2) Of the 60 cars sold, 30 had both power windows and a stereo.

OA:E

No Info is given on cars with only power windows and no stereo.So finding the number of cars without any power windows or stereo is not possible !!

2. In the xy-plane, does the point (4, 12) lie on line k ?
(1) The point (1, 7) lies on line k.
(2) The point (-2, 2) lies on line k
OA :C
Use both the options to find the slope.use Y=mX+C , we get the equation of the line.Substite the point(4,12) :)


In the rectangular coordinate system, are the points (r, s) and (u, v) equidistant from the origin ?
(1) r + s = 1
(2) u = 1 - r and v = 1 - s

OA : C
The Distance of a point (r,s) from the origin is Square root(r^2+s^2) and

The Distance of a point (u,v) from the origin is Square root(u^2+v^2)
so the question asked : Is r^2+s^2 = u^2+v^2

Squaringthe second option
U^2 = 1+R^2-2R and V^2 = 1 +S^2-2S
adding these two
U^2 + V^2 = R^2-2R+S^2-2S+2 = R^2 +S^2 +2-2(R+S)

From the 1st Option you cant answer the question, adding 1st and second option
U^2 + V^2 = R^2 +S^2 +2-2(R+S)
but R+S = 1
making it

U^2 + V^2 = R^2 +S^2

2. Is ab = 1 ?

(1) aba = a
(2) bab = b
OA : E :apologies: left the case where a and b are '0's
In the rectangular coordinate system, are the points (r, s) and (u, v) equidistant from the origin ?
(1) r + s = 1
(2) u = 1 - r and v = 1 - s
OA : C
The Distance of a point (r,s) from the origin is Square root(r^2+s^2) and
The Distance of a point (u,v) from the origin is Square root(u^2+v^2)
so the question asked : Is r^2+s^2 = u^2+v^2
Squaringthe second option
U^2 = 1+R^2-2R and V^2 = 1 +S^2-2S
adding these two
U^2 + V^2 = R^2-2R+S^2-2S+2 = R^2 +S^2 +2-2(R+S)
From the 1st Option you cant answer the question, adding 1st and second option
U^2 + V^2 = R^2 +S^2 +2-2(R+S)
but R+S = 1
making it
U^2 + V^2 = R^2 +S^2
2. Is ab = 1 ?
(1) aba = a
(2) bab = b
OA : D


OA is E for second Q
kapur.arnav Says
OA is E for second Q

updated my earlier post, thanks for correcting :biggrin:
1. After winning 50 percent of the first 20 games it played. Team A won all of the remaining games it played. What was the total number of games that Team A won?
(1) Team A played 25 games altogether
(2) Team A won 60 percent of all the games it played.
10. If r is represented by the decimal 0.t5, what is the digit t ?
1. r
2. r
1. After winning 50 percent of the first 20 games it played. Team A won all of the remaining games it played. What was the total number of games that Team A won?
(1) Team A played 25 games altogether
(2) Team A won 60 percent of all the games it played.


Both statements are sufficient.
Ans. D

Quote:
Originally Posted by kapur.arnav View Post
1. After winning 50 percent of the first 20 games it played. Team A won all of the remaining games it played. What was the total number of games that Team A won?
(1) Team A played 25 games altogether
(2) Team A won 60 percent of all the games it played.

Answer Otion D.. i.e. each of them are sufficient to give the answer

10. If
r is represented by the decimal 0.t5, what is the digit t ?
1. r
2. r
for rfor r
Hence, answer is option B, only r

10. If r is represented by the decimal 0.t5, what is the digit t ?
1. r
2. r


OA : B

Taking option 1 , rTaking option 2 , r
So option 2 alone is sufficient !!
1. After winning 50 percent of the first 20 games it played. Team A won all of the remaining games it played. What was the total number of games that Team A won?
(1) Team A played 25 games altogether
(2) Team A won 60 percent of all the games it played.


OA : D

Option 1 : Team A played 25 games, In the first 20 games it won 50% so that makes it 10 wins.In the next 5 matches it won all of them making the total number of wins 15

Option 2 : Team A won 60% of the games played. let the remaining matches be X, then ratio of wins to total matches = 10+X/20+X which stands at 60/100

10+X/20+X = 60/100

Simplifying it we get X = 5

we can answer the question by using any one of the options 😁

Can someone explain me what this question is asking for?

If 500 is the multiple of 100 that is closet to x and 400 is the multiple that is closet to y, which multiples of 100 is closet to x+y?

1) x2) y

Can someone explain me what this question is asking for?

If 500 is the multiple of 100 that is closet to x and 400 is the multiple that is closet to y, which multiples of 100 is closet to x+y?

1) x2) y

500 is the multiple of 100 that is closest to x so 451400 is the multiple of 100 that is closest to y so 351
***********************************************
Option 1 says

x
Combining these two , 802
so the nearest multiple of x+y are 800 or 900

You cant answer the question with this !!

************************************************

Option 2 says

y
Combining these two , 802
so the nearest multiple of x+y are 800 or 900

You cant answer the question with this !!

******************************************
Combining 1 and 2

so 451combining these two we get , 802
so the nearest multiple of x+y are 800 or 900

You cant answer the question combining these two

so OA : E

am i right
:confused: