Data Sufficiency

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Data Sufficiency

by Tagne » Mon Mar 14, 2011 12:57 pm
1. If ab not equal to 0 and points (-a,b) and (-b,a) are in the same quadrant of the XY plane, is point (-x,y) in this same quadrant?
a. xy>0
b. ax>0

2. If q is a positive integer less than 17 and r is the remainder when 17 is divided by q, what is the value of r?
a. q>10
b. q>2K where k is a positive integer

3. On a number line, the distance between point A and C is 5 and the distance between point B and point C is 20. Does point C lie between point A and point B?
a. The distance between point A and point B is 25
b. Point A lies to the left of point B

5. A certain group of car dealerships agreed to donate x dollars to a red cross chapter for each car sold during a 30-day period. What was the total amount that was expected to be donated?
a. A total number of 500 cars were expected to be sold
b. 60 more cars were sold than expected , so the total amount actually donated was $ 28,000
Source: — Problem Solving |

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by force5 » Mon Mar 14, 2011 1:32 pm
1. If ab not equal to 0 and points (-a,b) and (-b,a) are in the same quadrant of the XY plane, is point (-x,y) in this same quadrant?
a. xy>0
b. ax>0
IMO- C
a and b needs to have same sign ( from Question stem)

stmnt1 says xy>0 means same sign. positive or negative
but we dont know abt a or b ( insufficient)

stment2= ax>0 ( same sign) but dont know abt y ( insufficient)
combining

from 2 - a has same sign as x, from stem a and b have same signs, from stment1- x and y have same signs.
hence they all have same signs. [/quote]

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by srcc25anu » Mon Mar 14, 2011 1:36 pm
1. Q not clear
2. E
3. A
4. C
Last edited by srcc25anu on Mon Mar 14, 2011 4:26 pm, edited 1 time in total.

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by force5 » Mon Mar 14, 2011 1:42 pm
2. If q is a positive integer less than 17 and r is the remainder when 17 is divided by q, what is the value of r?
a. q>10
b. q>2K where k is a positive integer
I don't understand this question. If we solve this question the way its given then it doesn't make sense.

number is 17, divided by q
stmnt 1 = q can be 11, 12, 13, 14.... ( insufficient)
stmnt2 = q can be any number greater than 1
combining- still can be 11,13,15
Hence E ( please check the source once there has to be some error)

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by force5 » Mon Mar 14, 2011 1:52 pm
On a number line, the distance between point A and C is 5 and the distance between point B and point C is 20. Does point C lie between point A and point B?
a. The distance between point A and point B is 25
b. Point A lies to the left of point B

Good question
IMO - A
the following scenarios are possible

B---C---A; (BC = 20, CA = 5, BA = 25)
C---A---B; (CA = 5, CB = 20, AB = 15)
A---C---B; (AC = 5, CB = 20, AB = 25)
B---A---C; (BC = 20, AC = 5, BA = 15)

stment1- both 1st and 3rd fulfills however both have c in the center. ( sufficient)
stmnt2- 2nd and 3rd fulfills ( insufficient)

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by force5 » Mon Mar 14, 2011 2:01 pm
A certain group of car dealerships agreed to donate x dollars to a red cross chapter for each car sold during a 30-day period. What was the total amount that was expected to be donated?
a. A total number of 500 cars were expected to be sold
b. 60 more cars were sold than expected , so the total amount actually donated was $ 28,000

IMO- C

we need to find donation amount and total cars.
Stmnt1- expected cars sold ( but we dont have donation amount hence insufficient)
stment2- suppose expected = E then E+60 is sold. if $x is donated per car then

x(E+60) = 28000 ( insufficient)
combining.
stmnt 1 gives E and now we can solve.