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neokeynesian
10-16-2004, 10:42 AM
1)The area of a circular region having a radius of 1/4 meter is x square meters
Col A
x
Col B
1/4

2) (a+5)(a-5)=0
(b+5)(b-5)=0
Col A
a+5
Col B
b+5

3)Average (arithmetic mean) of Test Scores in Class R
Average score for the boys = 90
Average score for the girls = 81
Average score for the class = 84

Col A
The number of boys in the class who took the test
Col B
The number of girls in the class who took the test

4) At College C there are from 2 to 4 introductory philosophy classes each semester, & each of these classes has from 20 to 30 students enrolled. If one semester 10 percent of the students enrolled in introductory philosophy failed, what is the greatest possible number who failed?
a)12 b)10 c)8 d)6 e)3

5) Today is Jack's 12 th birthday and his father's 40th birthday. How many years from today will Jack's father be twice as old as Jack is at that time?
a)12 b)14 c)16 d)18 e)20

6) If the total surface area of a cube is 24, what is the volume of the cube?
a)8 b)24 c)64 d)48 sqrt 6 e)216

Answers: 1)b 2)d 3)b 4)a 5)c 6)a

calm_J
11-06-2004, 12:44 PM
1-area = (Pi) r^2 = (pi)*(1/4)^2 =( Pi)* 1/16 which is less than 1/4 then b is answer

2- answer is d. take this example a = 100 and b = 10
then a+5 > b+5
reverse them b=100 and a=10 then b+5 > a+5 thus undefined.

3- i think it's d not b .... can any1 clarify .... how could u know the no of boys and girls from the averages itself without the total no. of students. .... maybe i can't figure it out now as i want to go to bed ( more than 24 awake)

4- take the max of courses with the max of students then multiply by 10%

4*30*.1 = 12 student which is a

5- jack age at that time will be 12+x where x is the no. of years
his father will be twice as him means 2(12+x) also his father at that age will be 40+x
so 40+x= 24+2x ------ x=16 answer c

6- surface area = 6 L^2 where L is the length of leg

so L = 2 then volume = L^3 = 8 answer a

calm_J
11-06-2004, 12:52 PM
ohhh i got No 3 .... now i can go to sleep

assume that the total no. of boys and girls = n
the no. of boys = x
the no. of girls =y
now rephrase first sentence x+y=n-----------------------eqn1

now the average always is the total marks / no of students

so for boys and girls together (Total)/n=84-------------------eqn2
for boys (total of boys)/x = 90--------------------------------eqn3
for girls (total of girls)/y=81 ----------------------------------eqn4

now from eqn1, eqn 2, eqn3, eqn 4 and the fact that the total degrees for boys + total degrees for girls = total degrees

then 81y+90x=84 n
replacing n by x+y from eqn 1 then
81y+90X = 84x+84y