Part I
We have the size of the sheet of cardboard and we'll use the variable "x" to represent the length of the cuts. For any given cut, the available distance is reduced by twice the length of the cut. So we can create the following equations for length, width, and height.
width: w = 12 - 2x
length: l = 18 - 2x
height: h = x
Part II
v = l * w * h
v = (18 - 2x)(12 - 2x)x
v = (216 - 36x - 24x + 4x^2)x
v = (216 - 60x + 4x^2)x
v = 216x - 60x^2 + 4x^3
v = 4x^3 - 60x^2 + 216x
Part III
The length of the cut has to be greater than 0 and less than half the length of the smallest dimension of the cardboard (after all, there has to be something left over after cutting out the corners). So 0 < x < 6
Let's try to figure out an x that gives a volume of 224 in^3. Since this is high school math, it's unlikely that you've been taught how to handle cubic equations, so let's instead look at integer values of x. If we use a value of 1, we get a volume of:
v = 4x^3 - 60x^2 + 216x
v = 4*1^3 - 60*1^2 + 216*1
v = 4*1 - 60*1 + 216
v = 4 - 60 + 216
v = 160
Too small, so let's try 2.
v = 4x^3 - 60x^2 + 216x
v = 4*2^3 - 60*2^2 + 216*2
v = 4*8 - 60*4 + 216*2
v = 32 - 240 + 432
v = 224
And that's the desired volume.
So let's choose a value of x=2.
Reason?
It meets the inequality of 0 < x < 6 and it also gives the desired volume of 224 cubic inches.
The answer is B.
Hope it helps!
First you need to find how much 20% of $18.50 is. To do this, you need to multiply 18.50 by 20% which in decimal form is 0.2
$18.50x0.2=$3.70
Now you need to subtract $3.70 from $18.50
$18.50-$3.70=$14.80
Now that you have the new price, you need to find 6.75% of it to get the sales tax, so you multiply $14.80 by 6.75%, which is 0.0675 as a decimal.
$14.80x0.0675=$0.999 or $1
Now you add the sales tax to $14.80
$14.80+$1=$15.80 or $14.80+$0.999=$15.799
Answer:
C. since 8, 15, 17 are pythagorean triples
We have to find the expected value for the PlayBall lottery.
The price of the ticket = $1
Prize amount = $250
If a player wins, he will be winning $249 as the price is not paid back along with the prize amount. He is spending $1, getting back $250, so the net amount he is getting back is $249.
Now we have to find the probability of winning and losing.
Number of letters from A to T = 20
Number of digits from 0 to 9 = 10
Probability of picking up the same letter that was picked on that day = 1/20
Probability of picking up the same number that was picked on that day = 1/10
Thus, the Probability of picking up the same letter and same number that was picked on that day =
Thus, the probability of winning = 1/200
The probability of losing =
The expected value E for the PlayBall lottery will be:
Thus, the option C gives the correct answer