SECTIONS: 1 Learning Section & 1 Practice Section ( NOT FROM SAT TEST)
SCORE: 12/20
INCORRECT ANSWERS:
3. For which of the following graphs of f does f(x) = f(-x) for all values of x shown
Okay so i had answer choice C chosen at first because it hit -1, but i thought that since f(x) means y and y is height ,i erased it and put D because that shows height at -1.
I think if i have a thorough lesson on functions i won't have any problems on them.
5. Which of the following is an equation of the line that has a y intercept of 2 and an x intercept of 3?
*-2x+3y=4
*-2x+3y=6
*2x+3y=4
*2x+3y=6
*3x+2y=6
I don't know how the 6 got there? & I'm confused a little because i thought that the y intercept was 2, but isn't 6 the y intercept too?
6. In a certain game, each of 5 players received a score between 0 and 100, inclusive. If their average (arithmetic mean) score was 80, what is the greatest possible number of the 5 players who could have received a score of 50?
I don't know how to set up this equation.
10. Another Function Problem:
According to the table above, if k=f(3), what is the value of g(k)?
*1
*2
*3
*4
*5
11. In a certain school, there are k classes with n students in each class. If a total of p pencils are distributed equally among these students, how many pencils are there for each student?
*p/kn
*kn/p
*kp/n
*np/k
*npk
I used my own numbers, and i got kp/n. But that was wrong. I guess i need to start thinking about it without numbers?
5. Tim wrote a seven-digit phone number on a piece of paper. He later tore the paper accidentally and the last two digits were lost. What is the maximum number of arrangements of two digits, using the digits 0 through 9, that he could use in attempting to reconstruct the correct number?
I thought it would be 72 because i fell for two things:
1. I only thought there were 9 numbers i could use, but it was actually 10 because i didn't count the zero.
2. I also became more confused with a previous lesson that i had done in the workbook right before that, having to deal with permutations and combinations
7.One adult and 10 children are in an elevator . If the adults weight is 4 times the average (arithmetic mean) weight of the children, then the adults weight is what fraction of the total weight of the 11 people in the elevator?
Once again, i made up my own numbers. I know i shouldn't and I'll set up an equation next time.
1 comment:
1. F(x)= F (-x) is a question about symmetry across the Y axis.
Please read chapter 4 here for more background on functions
http://home.alltel.net/okrebs/index4.html
2. Intercepts. The y intercept is the X value when Y is 0. The X intercept is the Y value when X is 0. When there are equations in the answer sheet, that is a good time to plug in. You just have to plug in those values, and whenever something doesn't work, then you eliminate it. This is an easy one. Don't worry, you're going to get a lot more of this stuff in Algebra 2. You just need to cut down on mistakes not related to algebra, since you'll learn that stuff next year.
3. Ok, if their average score was 80 between 5 people... then they scored 400 points together between all of them. No one scored more than 100, but how many people could have scored 50s?
definitely not 5, because then all together they would only have 250 points
definitely not 4, because then the 4 people who scored 50s would have 200, and one more person would score 100 to get 300 points total
definitely not 3, because then the 3 people would add to 150, and 2 100s would add to 350
2 is possible. 100 points because 2 people get 50s, and then the other three people score hundreds, so 300 points there. Adds up to 400-- 400/5 is 80.
4. Easiest question here. K=f(3). Look up what f(x) is when x=3
f(x)=4
then, look up what g(x) is when the input is 4-- g(x)= 5
Read that stuff about functions.
5. Here, they are asking you to set up an equation. Don't plug in numbers here. Just set up the equation.
K*N gives the total # of students in the school
P is the total number of pencils given out
To get pencils per student, divide total pencils by total students
P/(K*N)
Yes, here, there are 10 different numbers that can be the 1st number, and 10 different numbers that can be the 2nd. So 20 numbers. You need to learn combinations and permutations well. Please skip a day of practice and learn/practice "functions" and "combo/permutions"
Finally, last question: yes, set up an equation. You are choosing all the wrong times to plug in and all the wrong times to set up. Let X equal the average weight of the children.
4X is the adult.
All of the children are 10X
Total weight is 14X
4X/14X, or 2/7ths after simplifying
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