The pack of pencils weighs 21.6 grams because 0.9 times 24 is 21.6
Solving a system of equations we will see that we need to use <u>40 liters of the 80% acid solution</u>, and the other <u>20 liters are of the 35% acid solution</u>.
<h3>
How many liters of each solution do we need to use?</h3>
First, we need to define the variables:
- x = liters of the 35% acid used.
- y = liters of the 80% acid used.
We know that we want to produce 60 liters of 65% acid, then we have the system of equations:
x + y = 60
x*0.35 + y*0.80 = 60*0.65
(in the second equation we wrote the percentages in decimal form).
To solve this we need to isolate one of the variables in one equation and then replace it in other one, isolating x we get:
x = 60 - y
Replacing that in the other equation:
(60 - y)*0.35 + y*0.80 = 60*0.65
y*(0.80 - 0.35) = 60*(0.65 - 0.35)
y*0.45 = 60*0.30
y = 60*0.30/0.45 = 40
So we need to use <u>40 liters of the 80% acid solution</u>, and the other <u>20 liters are of the 35% acid solution</u>.
If you want to learn more about systems of equations:
brainly.com/question/13729904
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Answer:
rational, integer, whole, natural, real
Step-by-step explanation:
Trailing zeros after the decimal point do not change the value of a number. This number is 1, a rational, real, integer, whole, natural number.
Answer:
144 lol
Step-by-step explanation:
Answer:
The population of the city in 2002 is 469,280 while the population of the suburb is 730,720.
Step-by-step explanation:
- 6% of the city's population moves to the suburbs (and 94% stays in the city).
- 2% of the suburban population moves to the city (and 98% remains in the suburbs).
The migration matrix is given as:
![A= \left \begin{array}{cc} \\ C \\S \end{array} \right\left[ \begin{array}{cc} C&S\\ 0.94&0.06 \\0.02&0.98 \end{array} \right]](https://tex.z-dn.net/?f=A%3D%20%5Cleft%20%5Cbegin%7Barray%7D%7Bcc%7D%20%20%5C%5C%20C%20%5C%5CS%20%5Cend%7Barray%7D%20%5Cright%5Cleft%5B%20%5Cbegin%7Barray%7D%7Bcc%7D%20%20C%26S%5C%5C%200.94%260.06%20%5C%5C0.02%260.98%20%5Cend%7Barray%7D%20%5Cright%5D)
The population in the year 2000 (initial state) is given as:
![\left[ \begin{array}{cc} C&S\\ 500,000&700,000 \end{array} \right]](https://tex.z-dn.net/?f=%5Cleft%5B%20%5Cbegin%7Barray%7D%7Bcc%7D%20%20C%26S%5C%5C%20500%2C000%26700%2C000%20%20%5Cend%7Barray%7D%20%5Cright%5D)
Therefore, the population of the city and the suburb in 2002 (two years after) is:
![S_0A^2=\left \begin{array}{cc} [500,000&700,000]\\& \end{array} \right\left \begin{array}{cc} \end{array} \right\left[ \begin{array}{cc} 0.94&0.06 \\0.02&0.98 \end{array} \right]^2](https://tex.z-dn.net/?f=S_0A%5E2%3D%5Cleft%20%5Cbegin%7Barray%7D%7Bcc%7D%20%5B500%2C000%26700%2C000%5D%5C%5C%26%20%20%5Cend%7Barray%7D%20%5Cright%5Cleft%20%5Cbegin%7Barray%7D%7Bcc%7D%20%5Cend%7Barray%7D%20%5Cright%5Cleft%5B%20%5Cbegin%7Barray%7D%7Bcc%7D%200.94%260.06%20%5C%5C0.02%260.98%20%5Cend%7Barray%7D%20%5Cright%5D%5E2)
![A^{2} = \left[ \begin{array}{cc} 0.8848 & 0.1152 \\\\ 0.0384 & 0.9616 \end{array} \right]](https://tex.z-dn.net/?f=A%5E%7B2%7D%20%3D%20%5Cleft%5B%20%5Cbegin%7Barray%7D%7Bcc%7D%200.8848%20%26%200.1152%20%5C%5C%5C%5C%200.0384%20%26%200.9616%20%5Cend%7Barray%7D%20%5Cright%5D)
Therefore:
![S_0A^2=\left \begin{array}{cc} [500,000&700,000]\\& \end{array} \right\left \begin{array}{cc} \end{array} \right \left[ \begin{array}{cc} 0.8848 & 0.1152 \\ 0.0384 & 0.9616 \end{array} \right]\\\\=\left[ \begin{array}{cc} 500,000*0.8848+700,000*0.0384& 500,000*0.1152 +700,000*0.9616 \end{array} \right]\\\\=\left[ \begin{array}{cc} 469280& 730720 \end{array} \right]](https://tex.z-dn.net/?f=S_0A%5E2%3D%5Cleft%20%5Cbegin%7Barray%7D%7Bcc%7D%20%5B500%2C000%26700%2C000%5D%5C%5C%26%20%20%5Cend%7Barray%7D%20%5Cright%5Cleft%20%5Cbegin%7Barray%7D%7Bcc%7D%20%5Cend%7Barray%7D%20%5Cright%20%5Cleft%5B%20%5Cbegin%7Barray%7D%7Bcc%7D%200.8848%20%26%200.1152%20%5C%5C%200.0384%20%26%200.9616%20%5Cend%7Barray%7D%20%5Cright%5D%5C%5C%5C%5C%3D%5Cleft%5B%20%5Cbegin%7Barray%7D%7Bcc%7D%20500%2C000%2A0.8848%2B700%2C000%2A0.0384%26%20500%2C000%2A0.1152%20%2B700%2C000%2A0.9616%20%5Cend%7Barray%7D%20%5Cright%5D%5C%5C%5C%5C%3D%5Cleft%5B%20%5Cbegin%7Barray%7D%7Bcc%7D%20469280%26%20730720%20%5Cend%7Barray%7D%20%5Cright%5D)
Therefore, the population of the city in 2002 is 469,280 while the population of the suburb is 730,720.
