Math Q

Discus: SAT/ACT Tests and Test Preparation: October 2003 Archive: Math Q
 By Akaflex (Akaflex) on Saturday, October 04, 2003 - 02:42 pm: Edit

A set of numbers is called a "unified" set if for every number x in the set, there is a number y in the set such that xy = 1. If the set {.1, .2, .5, 5, 10, k} is a unified set, what is the value of k?

A- 0
B- 1
C- 2
D- 15
E- 20

Is this how u approach the problem u multiply (.1)(.2)(.5)(5)(10) and u get .5 and then see which number it will multiply with to = 1?

 By Interested123 (Interested123) on Saturday, October 04, 2003 - 03:34 pm: Edit

C, u know .1 * 10 = 1 so eliminate those 2, .2 * 5 = 5 eliminate those 2, and that leaves u with .5 and k, .5 * k = 1 so k = 2.

 By Akaflex (Akaflex) on Saturday, October 04, 2003 - 03:54 pm: Edit

ANd heres another

S = {1 , 2, 3, 4, 5, 6}
T = {1, 2 , 3, 4, 5, 6,}

A number is to be chosen at random from set S, and then a number is to be chosen at ramdon from set T.

Col A.

Probability that the number chosen from set S will be 5

Col B.

The probability that the sum of the 2 numbers chosen will be 7

Can sum1 explain that and another one here too

The area of a field F is 20 sq yards. (1 yard = 3 feet)
Col A
The number of sq feet in the area of field F

Col B.
The probabiity that the sum of the 2 numbers chosen will be 7

 By Akaflex (Akaflex) on Saturday, October 04, 2003 - 04:00 pm: Edit

Interested i still dont see what u did and why u did it?

 By Akaflex (Akaflex) on Saturday, October 04, 2003 - 05:27 pm: Edit

BUMP

 By Gabypa (Gabypa) on Saturday, October 04, 2003 - 07:21 pm: Edit

tell me if im rite and ill explain

1.C 2. C

For 3. - are u sure u wrote Column B correctly?

 By Akaflex (Akaflex) on Saturday, October 04, 2003 - 07:56 pm: Edit

1 and 2 are correct

lol sorry on 3 COLUM B i ment to put 60

 By Chrisy (Chrisy) on Saturday, October 04, 2003 - 09:14 pm: Edit

C. 2 is correct. (.1x 10, .2x 5, .5x k)

 By Akaflex (Akaflex) on Saturday, October 04, 2003 - 10:00 pm: Edit

BUMP

 By Xiggi (Xiggi) on Saturday, October 04, 2003 - 11:18 pm: Edit

For the problem with probabilities, column A is 1/6 (1 number ot ouf 6) and Column B is 6/36 or 1/6. (combinations that yield 7 as total)

You can find the answers thru a couple of ways. The first is to write all the answers that total 7 (there are 6) and compare it to the maximum of 36 choices. There are 6 choices which is the same as for column A. You could also see that for WHATEVER number is picked in first set, there is only ONE possibility in set B to be a complement to 7. This means that there are only 6 choices.

For the problem with square feet, be careful of the trap 3 x 20 = 60. Remember that 1 square yard equals 9 square feet - 3x3=9.

 By Akaflex (Akaflex) on Sunday, October 05, 2003 - 11:36 am: Edit

what word in the world problem made u think .1 x 10 why did u do that, i dun even understand wut its asking plz help on this

 By Chrisy (Chrisy) on Sunday, October 05, 2003 - 08:17 pm: Edit

(.1x 10, .2x 5, .5x k)=1, thus k=2