Questions
In a certain town where all cars are either green or blue., there are 3 times...

In a certain town where all cars are either green or blue., there are 3 times more green cars than

the blue ones. Studies indicate that at a particularly dimly lighted pedestrian crossing at night the probability that a person correctly identifies the color of a green car is 0.68. The probability that they correctly identify the color of a blue car is 0.45. You were just hit by a car at that crossing and believe that the car was green.

i. Draw a probability tree representing these breakdowns.
ii. What is the probability that you were actually hit by a green car?

In: Advanced Math

Your swimming pool containing 84,000 gal of water has been contaminated by 6 kg of a...

Your swimming pool containing 84,000 gal of water has been contaminated by 6 kg of a nontoxic dye that leaves a swimmer's skin an unattractive green. The pool's filtering system can take water from the pool, remove the dye, and return the water to the pool at a flow rate of 250 gal/min.

(a) What is the initial value problem for the filtering process? Let q be the amount of dye in grams in the pool at any time t. dq dt = − 250q/84000​ Correct: Your answer is correct. g/min, q(0) = Correct: Your answer is correct. grams

(b) Solve the problem in part (a).

(d) Find the time T at which the concentration of the dye first reaches the value of 0.03 g/gal. (Round your answer to two decimal places.) T = hr

(e) Find the flow rate r that is sufficient to achieve the concentration 0.03 g/gal within 4 h. (Round your answer to the nearest integer.) r = gal/min

In: Advanced Math

Suppose f : [a, b] −→ R is continuous on [a, b] and that f attains...

Suppose f : [a, b] −→ R is continuous on [a, b] and that f attains its minimum value at ξ ∈ (a, b). If f ' (ξ) exists, prove that f ' (ξ) = 0.

In: Advanced Math

The Rams are playing the Aggies in the last conference game of the season. The Rams...

  1. The Rams are playing the Aggies in the last conference game of the season. The Rams are trailing the Aggies 21 to 14 with 7 seconds left in the game, when they score a touchdown. Still trailing 21 to 20, the Rams can either go for two points and win or go for one point to send the game into overtime. The conference championship will be determined by the outcome of this game. If the Rams win, they will go to the Candy Ball with a payoff of $6.4 million; if they lose they go to the Crocodile Bowl with a payoff of $1.2 million. If the Rams go for two points there is 30% chance they will be successful and 70% chance they will fail and lose. If they go for one point there is a 0.97 probability of success and 0.03 probability of failure. If they tie they will play overtime, in which the Rams have a 40% of winning because of fatigue.

  1. Draw a decision tree for this problem.
  2. What should the Rams do to achieve the highest expected monetary value (EMV) and what is the EMV?
  3. What would the Rams’ probability of winning the game in overtime have to be to make the Rams indifferent between going for one point or two points?

In: Advanced Math

Using the factorization of wave operator, derive the D’Alembert formula.

Using the factorization of wave operator, derive the D’Alembert formula.

In: Advanced Math

A tank initially contains 50 gallons of pure water. Starting at time t = 0 a...

A tank initially contains 50 gallons of pure water. Starting at time t = 0 a brine containing 2 pounds of dissolved salt per gallon flows into the tank at the rate of 3 gallons per minute. The mixture is kept uniform by stirring and the well stirred mixture simultaneously flows out of the tank at the same rate.

a) How much salt is in the tank at any time t > 0 ?

b) How much salt is present at the end of 25 minutes?

c) How much salt is present after a long time?

In: Advanced Math

show (b1+b2+...+bn)/n >= (b1b2...bn)^(1/n) Hint: do induction over k when n = 2k . Then for...

show (b1+b2+...+bn)/n >= (b1b2...bn)^(1/n)

Hint: do induction over k when n = 2k . Then for 2k−1 < n < 2k append to b1, b2, . . . , bn, 2 k − n equal numbers all equal to the arithmetic mean of the first n.

In: Advanced Math

QUESTION 4 [20 MARKS] T A company manufactures XPRINGLE and YPRINGLE products from Gold and Silver....

QUESTION 4 [20 MARKS] T A company manufactures XPRINGLE and YPRINGLE products from Gold and Silver. One XPRINGLE requires 5 grams of Gold and 4 grams of Silver while one YPRINGLE needs 4 grams of Gold and 3 grams of silver. The company has only 400 grams of Gold while it can use at least 120 grams of Silver. The production process must produce at least 10 of XPRINGLE. It should also produce at least 10 of YPRINGLE but cannot exceed 80 of this type. The profit for one XPRINGLE is P100 and for one YPRINGLE is P150. Let ? represent the number of XPRINGLE and ? represent the YPRINGLE. Required:

a. Formulate the linear programme for this production process clearly stating all the
constraints and the objective function.
b. Show the linear programme graphically.
c. Use the corner points to recommend the production mix that will maximize profit.
(4 minutes)
d. If the production process is allocated 990 min with the XPRINGLE taking 11 minutes
YPRINGLE taking 9 minutes, would the result obtained in (d)) above change? Explain
fully.

In: Advanced Math

Apply single linkage clustering to these schools until only one option remains. What conclusions can you...

Apply single linkage clustering to these schools until only one option remains. What conclusions can you make from this analysis?

Berkeley

Cal Tech

UCLA

UNC

Berkeley

0

6.30407

1.19454

1.64918

Cal Tech

0

6.71434

7.17959

UCLA

0

2.19821

UNC

0

In: Advanced Math

Arithmetic in the AES MixColumns operation (22 marks) Recall that the MixColumns operation in AES performs...

Arithmetic in the AES MixColumns operation
Recall that the MixColumns operation in AES performs arithmetic on 4-byte vectors using the
polynomial M(y) = y4 + 1. In this arithmetic, we have M(y) = 0, so y4 = 1.
(a) In this part of the problem, we consider multiplication of 4-byte vectors (viewed as polyno-
mials of degree ≤ 3 whose coefficients are bytes) by powers of y.
i. Formally prove that in this arithmetic, multiplication of any 4-byte vector by y is a circular left shift of the vector by one byte.
ii. Prove that in this arithmetic, yi = yj for any integer i ≥ 0, where j ≡ i (mod 4) with 0 ≤ j ≤ 3.
iii. Use part (a) (ii) to formally prove that multiplication of any 4-byte vector byyi (i≥0)isacircularleftshiftofthevectorbyjbytes,wherej≡i(mod4)with 0 ≤ j ≤ 3.
(b) Next, we consider arithmetic involving the coefficients of the polynomial c(y) = (03)y3 + (01)y2 + (01)y + (02) ,
that appears in MixColumns, where the coefficients of c(y) are bytes written in hexadeci- mal (i.e. base 16) notation. Arithmetic involving this polynomial requires the computation of products involving the bytes (01), (02) and (03) in the Rijndahl field GF(28). Recall that in this field, arithmetic is done modulo m(x) = x8 + x4 + x3 + x + 1.
i. Write the bytes (01), (02), (03) as their respective polynomial representatives c1(x), c2(x) and c3(x) in the Rijndahl field GF(28).
ii. Let b = (b7 b6 ···b1 b0) be any byte, and let d = (02)b be the product of the bytes (02) and b in the Rijndahl field GF(28). Then d is again a byte of the form d = (d7 d6 · · · d1 d0). Provide symbolic expressions for the bits di, 0 ≤ i ≤ 7, in terms of the bits bi of b.
iii. Provide analogous expressions as in part (b) (ii) for the byte product e = (03)b, where b = (b7 b6 ···b1 b0) is any byte.
(c) The
mial c(y) of part (b). In this part of the problem, you will evaluate such products symbol- ically.
1
MixColumns operation performs multiplication of 4-byte vectors by the polyno-

i. Let s(y) = s3y3+s2y2+s1y+s0 be a polynomial whose coefficients are bytes. Symbolically compute the product t(y) = s(y)c(y) mod y4 + 1. The result should be a polynomial of the form t(y) = t3y3+t2y2+t1y+t0 where t3,t2,t1,t0 are bytes. Provide symbolic expressions for the bytes ti, 0 ≤ i ≤ 3, in terms of the bytes si. The equations should consist of sums of byte products of the form 01si, 02si, 03si, 0 ≤ i ≤ 3. You need not compute these individual byte products as you did in part (b).
ii. Write your solution of part (c) (i) in matrix form; i.e. give a 4 × 4 matrix C whose entries are bytes such that
 t0   s0   t1  = C  s1 
  t2   s2 
t3 s3
Note that this yields the matrix representation of MixColumns presented (without
proof) in class.

In: Advanced Math

A manufacturer of sports equipment has developed a new synthetic fishing line that he claims has...

A manufacturer of sports equipment has developed a new synthetic fishing line that he claims has a mean breaking strength of 8 kilograms. If a random sample of 20 lines is tested and found to have a sample mean breaking strength of 7.8 kilograms with a sample variance of 0.25. By using hypothesis testing, does this suggest at a 0:01 level of significant that the mean breaking strength is not 8 kilograms? Assume the population of the breaking strength to be normal.

In: Advanced Math

Let F be a subfield of a field E, and let u in E be given....

Let F be a subfield of a field E, and let u in E be given. Prove that u is algebraic over F if and only if [F(u):F]

[F(u):F] is finite

In: Advanced Math

MATHEMATICS REFLECTION (essay type minimum of 10 sentences) explain the relevance of social choice theory in...

MATHEMATICS REFLECTION (essay type minimum of 10 sentences)
explain the relevance of social choice theory in tackling social problems (mathematics in the modern world)

In: Advanced Math

What are your views in learning the concepts discussed in this course? Are there topics/concepts that...

What are your views in learning the concepts discussed in this course? Are there topics/concepts that are too easy or too difficult to understand (general MATHEMATICS in the modern world)

In: Advanced Math

. Use the Taylor expansion of the function f(z) = 1 1+z [8] 4 centred at...

. Use the Taylor expansion of the function f(z) = 1 1+z [8] 4 centred at the origin z = 0, together with the extended Cauchy Integral Formula to evaluate the contour integrals I C dz/ z^ k (z^ 4 + 1), k = 0, 1, . . . , where C is any positively oriented simple contour going around the origin that is interior to the circle of radius 1 centred at z = 0.

In: Advanced Math