Answer:
The use of 15% solution be 18 ounce and the use of 40% solution be 12 ounce .
Step-by-step explanation:
Let us assume that the use of 15% solution be x .
Let us assume that the use of 40% solution be y .
As given
A chemist needs to make 30 ounces of a 25% alcohol solution by mixing together a 15% alcohol solution with a 40% alcohol solution.
Equation becomes
x + y = 30
25 % is written in the decimal form .
[tex]= \frac{25}{100}[/tex]
= 0.25
15 % is written in the decimal form .
[tex]= \frac{15}{100}[/tex]
= 0.15
40 % is written in the decimal form .
[tex]= \frac{40}{100}[/tex]
= 0.40
Equation becomes
0.15x + 0.40y = 30 × 0.25
[tex]\frac{15x}{100} + \frac{40}{100} = \frac{30\times 25}{100}[/tex]
Simplify the above
15x + 40y = 750
Two equations are
x + y = 30
15x + 40y = 750
Multiply x + y = 30 by 15 and subtracted from 15x + 40y = 750.
15x - 15x + 40y - 15y = 750 - 450
25y = 300
[tex]y = \frac{300}{25}[/tex]
y = 12
Puttiny the value of y in the x + y = 30 .
12 + x = 30
x = 30 - 12
x = 18
Therefore the use of 15% solution be 18 ounce and the use of 40% solution be 12 ounce .
