MATHEMATICS COLLEGE

On a snowy evening only 2/3 of the registered students in Bob's chessclass came to school. Eighteen students attended that night. How
many students are registered in Bob's class?

Answers

Answer 1
Answer: 18 / 2 = 9 || 9 x 3 = 27. Therefore, 27 students are registered in Bob’s class.

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If 10 students each own 10 pencils, which expression matches how many in total pencils they?
Cuánto le falta a 3/5para llegar a 9/10
Jonah weighs his puppy each week. The puppy has a mass of 10 kilograms the first time Jonah weighs it. The mass of the puppy increases0.5 kilograms each week until it is fully grown. For each of the answer options, let y represent mass in kilograms, and x represent time inweeks.Which equation shows a smaller rate of change than Jonah's puppy?O A. y = 0.4x + 10OB. y=0.5x + 9OC. y = 9x +0.5D. y = 10x +0.4
Luis is doing his math homework. He has 30 problems in all. After an hour, he only has 1/6 of those problems left. How many problems does he have left?

Use the following results from a test for marijuana use, which is provided by a certain drug testing company. Among 147 subjects with positive test results, there are 30 false positive results; among 157 negative results, there are 4 false negative results. If one of the test subjects is randomly selected, find the probability that the subject tested negative or did not use marijuana. (Hint: Construct a table.)a. The probability that a randomly selected subject tested negative or did not use marijuana is___________.
(Do not round until the final answer. Then round to three decimal places as? needed.)
b. How many subjects were included in the study?
The total number of subjects in the study was___.
c. How many subjects did not use marijuana?
A total of ___subjects did not use marijuana.

Answers

Answer:

(a)0.615

(b)304

(c)183

Step-by-step explanation:

Among 147 subjects with positive test results, there are 30 false positive (actually negative) results;

Among 157 negative results, there are 4 false-negative (actual positive) results.

The table below summarises the given data.

\left\begin{array}{c|c|c|cc}&$Use Marijuana&$Did Not Use Marijuana&$Total\n---&-------&-------&-------\n$Positive Result&117&30&147\n$Negative Result&4&153&157\n---&-------&-------&-------\n$Total&121&183&304\end{array}\right

(a)The probability that a randomly selected subject tested negative or did not use marijuana

P(negative or did not use marijuana)

=P(negative)+P(did not use marijuana)-P(both)

=(157)/(304)+ (183)/(304)-(153)/(304)\n=(187)/(304)\n\n\approx 0.615

(b)There were a total of 304 subjects in the study.

(c)A total of 183 subjects did not use marijuana.

Which expression is equivalent to (m2p–2r7)(m–5p4r2)?

Answers

Answer:

=(m2p+−2r7)(m+−5p4r2)

=(m2p)(m)+(m2p)(−5p4r2)+(−2r7)(m)+(−2r7)(−5p4r2)

=m3p−5m2p5r2−2mr7+10p4r9

=10p4r9−5m2p5r2−2mr7+m3p

Step-by-step explanation:

:D

What are the coordinates of the point on the directed line segment from (-6, -3) to(5,8) that partitions the segment into a ratio of 6 to 5?

Answers

Given:

A point divides a directed line segment from (-6, -3) to (5,8) into a ratio of 6 to 5.

To find:

The coordinates of that point.

Solution:

Section formula: If point divides a line segment in m:n, then the coordinates of that point are

Point=\left((mx_2+nx_1)/(m+n),(my_2+ny_1)/(m+n)\right)

A point divides a directed line segment from (-6, -3) to (5,8) into a ratio of 6 to 5. Using section formula, we get

Point=\left((6(5)+5(-6))/(6+5),(6(8)+5(-3))/(6+5)\right)

Point=\left((30-30)/(11),(48-15)/(11)\right)

Point=\left((0)/(11),(33)/(11)\right)

Point=\left(0,3\right)

Therefore, the coordinates of the required point are (0,3).

the same type of television is being sold at two different stores. store A is selling the television for $800, which is $120 more than half the cost of the television at store B. write and solve an equation to determine the selling price for the television at store B.

Answers

Answer: the selling price of the television at store B is $1360

Step-by-step explanation:

Assuming the selling price of the television at store B is represented by $B. Store A is selling the television for $800, which is $120 more than half the cost of the television at store B. The equation representing this situation is expressed as

800 = B/2 + 120

Multiplying the left hand side and the right hand side of the equation by 2, it becomes

1600 = B + 240

B = 1600 - 240

B = $1360

What is the reciprocal of 5/6​

Answers

Answer:

6/5

The reciprocal is just the numbers flipped.

Answer:

-6/5

Hope this helps!

Suppose that 30% of all students who have to buy a text for a particular course want a new copy (the successes!), whereas the other 70% want a used copy. Consider randomly selecting 15 purchasers.The bookstore has 10 new copies and 10 used copies in stock.
If 15 people come in one by one to purchase this text, what is the probability that all 15 will get the type of book they want from current stock?

Answers

Answer:

The probability that all 15 will get the type of book they want from current stock is 0.4838.

Step-by-step explanation:

Denote the random variable Xas the number of students who want to buy new copy.

The probability of a student wanting to buy a new copy is, P (X) = p = 0.30.

A random sample of n = 15 students is selected.

The random variable X follows a Binomial distribution.

The probability function of a Binomial distribution is:

P(X=x)={n\choose x}p^(x)(1-p)^(n-x);\ x=0, 1, 2, 3,...

It is provided that the bookstore has 10 new copies and 10 used copies in stock.

All the 15 students get their desired copy, then this can happen if at most 10 want to buy new copy and at least 5 wants to buy used copy.

Compute the probability of (5 ≤ X ≤ 10) as follows:

P (5 ≤ X ≤ 10) = P (X = 5) + P (X = 6) + P (X = 7) + P (X = 8) + P (X = 9) + P (X = 10)

                     ={15\choose 5}(0.30)^(5)(1-0.30)^(15-5)+{15\choose 6}(0.30)^(6)(1-0.30)^(15-6)\n+{15\choose 7}(0.30)^(7)(1-0.30)^(15-7)+{15\choose 8}(0.30)^(8)(1-0.30)^(15-8)\n+{15\choose 9}(0.30)^(9)(1-0.30)^(15-9)+{15\choose 10}(0.30)^(10)(1-0.30)^(15-10)\n=0.2061+0.1472+0.0811+0.0348+0.0116+0.0030\n=0.4838

Thus, the probability that all 15 will get the type of book they want from current stock is 0.4838.
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