Ask question

Ask question

All categories

Bad White [126]

3 years ago

5

A scientist has two solutions, which she has labeled Solution A and Solution B. Each contains salt. She knows that Solution A is

65% salt and Solution B is 90% salt. She wants to obtain 120 ounces of a mixture that is 75% salt. How many ounces of each solution should she use?

1 answer:

BigorU [14]3 years ago

8 0

Answer:

48 oz of 90% (B)
72 oz of 65% (A)

Step-by-step explanation:

The amount of salt in the mixture is the sum of the amounts of salt in the constituents. Those amounts are found by multiplying the quantity of solution by the percentage that is salt.

__

Let x represent the quantity of 90% salt solution B, in ounces. Then the number of ounces of salt in the mix is ...

0.90x +0.65(120 -x) = 0.75(120)

0.25x = 0.10(120) . . . . . . subtract 0.65(120) and simplify

x = 48 . . . . . . . . . . . . . divide by 0.25

120 -x = 72 . . . . . . . amount of 65% solution A

She should use 48 ounces of 90% solution B, and 72 ounces of 65% solution A.

You might be interested in

In an arithmetic sequence, the nth term an is given by the formula an=a1+(n−1)d, where a1 is the first term and d is the commo

Dmitry_Shevchenko [17]

Answer:

$a_{10} = \frac{10}{65536}$

Step-by-step explanation:

The first step to solving this problem is verifying if this sequence is an arithmetic sequence or a geometric sequence.

This sequence is arithmetic if:

$a_{3} - a_{2} = a_{2} - a_{1}$

We have that:

$a_{3} = 40, a_{2} = 10, a_{3} = \frac{5}{2}$

$a_{3} - a_{2} = a_{2} - a_{1}$

$\frac{5}{2} - 10 = 10 - 40$

$\frac{-15}{2} \neq -30$

This is not an arithmetic sequence.

This sequence is geometric if:

$\frac{a_{3}}{a_{2}} = \frac{a_{2}}{a_{1}}$

$\frac{\frac{5}[2}}{10} = \frac{10}{40}$

$\frac{5}{20} = \frac{1}{4}$

$\frac{1}{4} = \frac{1}{4}$

This is a geometric sequence, in which:

The first term is 40, so $a_{1} = 40$

The common ratio is $\frac{1}{4}$ , so $r = \frac{1}{4}$ .

We have that:

$a_{n} = a_{1}*r^{n-1}$

The 10th term is $a_{10}$ . So:

$a_{10} = a_{1}*r^{9}$

$a_{10} = 40*(\frac{1}{4})^{9}$

$a_{10} = \frac{40}{262144}$

Simplifying by 4, we have:

$a_{10} = \frac{10}{65536}$

3 0

4 years ago

Suppose that X is a random variable with mean 30 and standard deviation 4. Also suppose that Y is a random variable with mean 50

Vladimir79 [104]

Answer:

a) Var[z] = 1600

D[z] = 40

b) Var[z] = 2304

D[z] = 48

c) Var[z] = 80

D[z] = 8.94

d) Var[z] = 80

D[z] = 8.94

e) Var[z] = 320

D[z] = 17.88

Step-by-step explanation:

In general

V([x+y] = V[x] + V[y] +2Cov[xy]

how in this problem Cov[XY] = 0, then

V[x+y] = V[x] + V[y]

Also we must use this properti of the variance

V[ax+b] = $a^{2}$ V[x]

and remember that

standard desviation = $\sqrt{Var[x]}$

a) z = 35-10x

Var[z] = $10^{2}$ Var[x] = 100*16 = 1600

D[z] = $\sqrt{1600}$ = 40

b) z = 12x -5

Var[z] = $12^{2}$ Var[x] = 144*16 = 2304

D[z] = $\sqrt{2304}$ = 48

c) z = x + y

Var[z] = Var[x+y] = Var[x] + Var[y] = 16 + 64 = 80

D[z] = $\sqrt{80}$ = 8.94

d) z = x - y

Var[z] = Var[x-y] = Var[x] + Var[y] = 16 + 64 = 80

D[z] = $\sqrt{80}$ = 8.94

e) z = -2x + 2y

Var[z] = 4Var[x] + 4Var[y] = 4*16 + 4*64 = 320

D[z] = $\sqrt{320}$ = 17.88

7 0

3 years ago

What is an example of a non-statistical question? Question 1 is because of winn dixie your favorite book

lozanna [386]

Answer:

examples of non-statistical questions are: how old are you?

Step-by-step explanation:

Non-Statistical Questions. The next type of question is the non-statistical question. This is the type of question that only has one answer. This one answer also doesn't change. You don't need to gather several points of data to answer the question.

7 0

4 years ago

Read 2 more answers

HELP PLEASEEE!!

Luden [163]

$\left[\begin{array}{ccc}2&6&3\\-5&1&4\end{array}\right]$

R1 ÷ 2 = $\left[\begin{array}{ccc}1&3&1.5\\-5&1&4\end{array}\right]$

R2 ÷ -5 = $\left[\begin{array}{ccc}1&3&1.5\\1&-0.2&-0.8\end{array}\right]$

R2: R1 - R2 = $\left[\begin{array}{ccc}1&3&1.5\\0&3.2&2.3\end{array}\right]$

R2 ÷ 3.2 = $\left[\begin{array}{ccc}1&3&1.5\\0&1&0.71875\end{array}\right]$

R1: R1 - 3R2 = $\left[\begin{array}{ccc}1&0&0.65625\\0&1&0.71875\end{array}\right]$

Answer: x = 0.65625, y = 0.71875

8 0

3 years ago

How can I solve this?

Eva8 [605]

Answer:

they are congruent so 47 is also the measurement for its corresponding angle(aka the corner that doesn't have a variable)

and in a triangle, interior angles add to 180 so 47+x+y=180

90 + 43 = 133

+47= 180

so your answer is a

hope this helps!!

8 0

3 years ago