If Sandra mixes <em>x</em> L of 65% solution with <em>y</em> L of 90% solution, then the resulting mixture has a total volume of
<em>x</em> + <em>y</em> = 500
litres, and it contains
0.65<em>x</em> + 0.90<em>y</em> = 0.75 (500) = 375
litres of alcohol.
Solve the first equation for <em>y</em> :
<em>y</em> = 500 - <em>x</em>
<em />
Substitute this into the second equation and solve for <em>x</em> :
0.65<em>x</em> + 0.90 (500 - <em>x</em>) = 375
0.65<em>x</em> + 450 - 0.90<em>x</em> = 375
75 = 0.25<em>x</em>
<em>x</em> = 300
Solve for <em>y</em> :
<em>y</em> = 500 - 300
<em>y</em> = 200
So, Sandra should mix 300 L of 65% solution with 200 L of 90% solution.
Complete Question
A hypothetical population consists of eight individuals ages 13 14 17 20 21 22 24 30 years.
A: what is the probability that a person in this population is a teenager?
B: what is the probability of selecting a participant who is at least 20 years old?
We have that probability that a person in this population is a teenager and probability of selecting a participant who is at least 20 years old is
From the question we are told
A hypothetical population consists of eight individuals ages 13, 14, 17, 20, 21, 22, 24, & 30 years.
a)
Generally the equation for the probability that a person in this population is a teenager is mathematically given as

P(T)=0.38
b)
Generally the equation for the probability of selecting a participant who is at least 20 years old is mathematically given as

P(T')=0.63
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Answer:

Step-by-step explanation:


Answer:
x=8
Step-by-step explanation:
Triangle DCE is similar to EGF
CE/EF=DE/EG
Substitute
(8x-1)/21=(6x+3)/17
Cross multiply
(8x−1)*(17)=(6x+3)*(21)
136x−17=126x+63
Subtract 126x from both sides
10x−17=63
Add 17 to both sides.
10x−17+17=63+17
10x=80
Divide both sides by 10.
x=8
it is 34,731,629 gust put the numbers to gater