i need help wiht math problems~

<p>they are from the new BB</p>

<p>TEST 1 Section 8 #16
n(t)=(t^2)/2-20t+k
There was a 100-day period when the number of bees in a certain hive could be modeled by the function of n above. in the function, k is a constant and n(t) represents the number of bees on day number t for 0<t<99 (both smaller and greater or equal respectively). on what number day was the number of bees in the hive the same as it was on day number 10?</p>

<p>Test 2 section 8 #8
A box contains wood beads, red glass beads, and blue glass beads. the number of glass beads is 4 times the number of wood beads. if one bead is to be chosen at random from the box, the probability that a red class bead will be chosen is 3 times the probability that a blue glass bead will be chose. if there are 12 red glass beads in the box, what is the toatal number of beads in the box ?
a. 20
b. 45
c. 48
d. 60
e. 90</p>

<p>the answer is letter a.</p>

<h1>16</h1>

<p>On a square gameboard that is divided into n rows of n squares each, k of these squares lie aolng the boundary of the gameboard. which of the following is a possible value for k?
a. 10
b. 25
c. 34
d. 42
e. 52</p>

<p>the answer is letter e.</p>

<p>test 2 section 5 # 18
it has a picture but i dont know how to put a link here..
it would be great if somebody checks the book and explain it to be how to solve it.</p>

<p>thank you in advance :)</p>

<h1>8- The ratio of glass to wood is 4:1. Red to blue is additionally 3:1 (since its three times as likely to be chosen). 12 is four times three, so multiply the initial ration (4:1) by 4, which gives 16:4. 16+4 = 20, answer (A)</h1>

<h1>16- A quick diagram shows that k=2n. k then, cannot be odd, as it is divisible by two, eliminating (B). In addition, there cannot be an odd number of squares (n) and so dividing by two should yield an even number. (e) is the only answer that should fit this criteria. 52/2=26.</h1>

<p>Sorry if my explanations aren’t concise, perhaps someone can pose an alternate solution.</p>

<p>for the first 16 its pretty simple as well, </p>

<p>plug in 10 and see you get -150 + K </p>

<p>a quick glance at the answers and you know it wont be A C or E because they will all come out to even hundreds when ^2 /2 so you’re down to B & D</p>

<p>from here you can eliminate D because 50^2 /2 (same thing as 25<em>50) is still greater than 20</em>50 so you know it will leave a positive number to add to K, </p>

<p>leaving you with only answer choice B, and we barely had to do any math, rofl</p>

<p>for the second #16,</p>

<p>i’m not sure if i’m reading the problem wrong but i believe k = 4n - 4 = 4(n-1) where 4n accounts for the squares on the sides and subtracting 4 deals with the overlapping sides at the corners. keeping in mind that n is a positive integer you can then work backwards and plug in values for k from the answers, looking for one that is divisible by 4 to ensure n is an integer:</p>

<p>a. 10/4 = decimal!
b. 25/4 = decimal again
c. 34/4 = decimal
d. 42/4 = decimal
e. 52/4 = 13, ahah! you are now left with n - 1 = 13, or n = 14 squares per side. e is the correct answer =]</p>