some real old SAT math problems help!!!

<li>If J is chosen at random from the set {4,5,6} and k is chosen at random from the se {10.11.12}, what is the probability that the product of j and k is divisible by 5?</li>
</ol>

<p>2.tx+12y=-3
the equation above is the equation of a line in the xy-plane, and t is a constant. if the slope of the line is -10, what is the value of t?</p>

<li>A sphere of radius r inside a cube touches each one of the six side of the cube. what is the volue of the cube,in terms of r?</li>
</ol>

<p>4.when a certain odd number is divided by 5, the remainder is 1. which digit must be in the units place of this odd number? A)1 B)3 C)5 D)7 E)9</p>

<p>5.The number n is a 2digit number. when n is divided by 10, the remainder is 9, when n is divided by 9, the remainder is 8. what is the value of n?</p>

<li><p>In the xy-plane, the graph of the function f is a line. if f(2)=7 and f(12)=1, what is the value of f(7)?A)5.2 B)5 C)4.6 D)4 E)3.4</p></li>
<li><p>Tom and Alison are both salespeople. tom’s weekly compensation consists of $300 plus 20 percent of his sales. Alison’s weekly compesation consists of $200 plus 25 percent of her sales. if they both had the same amount of sales and the same compensation for a particular week, what was that compensation, in dollars?</p></li>
</ol>

<p>8.</p>

<p>x -1 0 1
f(x) 1/8 1/2 2</p>

<p>the table shows some values for the function f. the f(x)=ka^x for some constants k and a. what is the value of a?</p>

<li><p>the sum of the positive odd integers less than 100 is subtracted from the sum of the positive even integers less than or equal to 100. what is the resulting difference?</p></li>
<li><p>f(x)=kg(x)+2
the function f above is defined in terms of another function g for all values of x, where k is a constant if t is a number for which f(t)=30 and g(t)=8. what does k equal?</p></li>
<li><p>Barb’s motor scooter has a 2-gallon gas tank and can travel m miles on 1 gallon of gas. If gas costs $1.25 per gallon and Barb spends d dollars to fill the tank, which of the following represents the amount of gas, in gallons, that was in the tank before she filled it?</p></li>
<li><p>0 0 X(shaded note) 0</p></li>
</ol>

<p>a student practices the four musical notes above starting with the note furthest left and continuing in order from left to right. If the student plays these notes over and over according to this pattern and stops immediately after playing the shaded note. which of the following could be the total number of notes played?</p>

<p>13.n(t)=500(0.81)^t
the function above can be used to model the population of a certain endangered species of animal. if n(t) gives the number of the species living t decades after the year 1900, which of the following is true about the population of the species from 1900 to 1920?</p>

<p>A)it increased by about 1000
B)it increased by about 320
C)it decreasedby about 180
D)it decreased by about 320
E)it decreased by about 1000</p>

<p>thx alot!!!</p>

<ol>
<li>j (4,5,6) k (10,11,12)
the only way to be a multiple of 5 is to multiply by a multiple of 5.
only j(5) and k(10) can do that.
so 5 (10,11,12) and 10 (4,5,6)</li>
</ol>

<p>6/9 = 2/3</p>

<ol>
<li>tx+12y=-3
12y= -tx -3
y= (-tx)/12 - (-1/4)
-10 = (-t/12)
-120=-t
120=t</li>
</ol>

<p>3.
4. 41/5 = 8 r 1.
the answer is A</p>

<ol>
<li><p>89/10 = 8 r 9.
89/9 = 9 r 8
answer is 89</p></li>
<li><p>midpoint.
[ (12+2)/2) ],[(7+1)/2 ]
point is (7,4)</p></li>
</ol>

<p>D</p>

<ol>
<li><p>300+.2x=200+.25x
100=.05x
2000=x</p></li>
<li><p>C
500(.81^(2)) - 500(.81^(0))</p></li>
</ol>

<p>1) i think it's 2/3
2) =120 i b'lieve
3) 8r^3
4) A, 1
5) 89
6)</p>

<p>1.) It's 5/9. The total number of possible combinations is 9 and the probablity of j and k being divisible by 5 is: 4 x 10, 5 x 10, 5 x 11, 5 x 12, and 6 x 10 which are a total of 5 combinations.
2.) t=120
4.) A
8.) a=4
10.) k=3.5 or 7/2</p>

<p>To anhtimmy </p>

<p>thank you so much!!!
umm.for second question..
y= (-tx)/12 - (-1/4)
-10 = (-t/12)--->how u get this?why u get rid of x???sorry ..im so dumb at math=.=</p>

<p>sooo,for the 5th question..u just try numbers?????</p>

<p>To Truplayer287 </p>

<p>can u explain #8 and #10 please...im so confuse with the constant and function...
and what concept should i review for these kind of questions???</p>

<p>thx</p>

<p>to jagthebeetle </p>

<p>thx alot</p>

<p>for tx+12y= -3
12y= -tx-3
y= (-tx)/12 - (1/4)
then -t/12 = -10 because y=mx+b, m=slope
-120 = -t
t= 120</p>

<p>to central1 </p>

<p>ohhh i see..i got it..i wrote down the formula but i didnt realize it..=.= how dumb i am</p>

<p>anyways..thx alot..</p>

<p>and for #13..
why is 500(.81^(2)) - 500(.81^(0))
where is 500(.81^(2)) come from??</p>

<p>n(t)=500(0.81)^t
n(t)=500(0.81)^2 (because 2 decades=20 yrs)
n(t)=328</p>

<p>increased 328 = B, increased about 320</p>

<p>you don't need to subract from starting point bc it says n(t) gives the number of the species living t decades after the year 1900</p>

<p>For #5 u first find the L.C.M. of 9 & 10 (i.e. 90) and then look for a nearby no. that satisfies the condition.</p>

<p>For #8 take the value x=0
f(x)=ka^x
1/2=ka^0
k=1/2
now take any value
f(x)=ka^x
2=(1/2)a^1
a=4</p>

<h1>10 just substitute all the values & u'll get</h1>

<p>30=8k+2
and k=3.5</p>

<p>wow, how come i didn't see this thread?
Any questions left to answer?</p>

<p>5.The number n is a 2digit number. when n is divided by 10, the remainder is 9, when n is divided by 9, the remainder is 8. what is the value of n?</p>

<p>---> This means that (n+1) is divisible by both 9 and 10
so n+1 = 90
n = 89</p>

<ol>
<li>0 0 X(shaded note) 0</li>
</ol>

<p>a student practices the four musical notes above starting with the note furthest left and continuing in order from left to right. If the student plays these notes over and over according to this pattern and stops immediately after playing the shaded note. which of the following could be the total number of notes played?</p>

<p>---> The answer will be the value among the given options which is of the form (4k + 3) where k is a whole number.</p>

<ol>
<li>Barb's motor scooter has a 2-gallon gas tank and can travel m miles on 1 gallon of gas. If gas costs $1.25 per gallon and Barb spends d dollars to fill the tank, which of the following represents the amount of gas, in gallons, that was in the tank before she filled it?</li>
</ol>

<p>---> 2 - (d/1.25) gallons</p>

<ol>
<li>The sum of the positive odd integers less than 100 is subtracted from the sum of the positive even integers less than or equal to 100. what is the resulting difference?</li>
</ol>

<p>----> (2 + 4 + 6 ... + 100) - (1 + 3 + 5 ... + 99)
= 1 + 1 + 1 ... 50 times
= 50</p>

<p>to spideyunlimited </p>

<p>wow..thx thx........I LOVE YOU SO MUCH..lolz</p>

<p>To spideyunlimited</p>

<p>(4k + 3)--->where is this form come from???
and can u explain #11 lil bit????thx</p>