Assume that the amount needed from the 5% solution is x and that the amount needed from the 65% solution is y.
We are given that, the final solution should be 42 ml, this means that:
x + y = 42 ...........> equation I
This can also be written as:
x = 42-y .......> equation II
We are also given that the final concentration should be 45%, this means that:
5% x + 65% y = 45% (x+y)
0.05x + 0.65y = 0.45(x+y)
We have x+y = 42 from equation I, therefore:
0.05x + 0.65y = 0.45(42)
0.05x + 0.65y = 18.9 .........> equation III
Substitute with equation II in equation III as follows:
0.05x + 0.65y = 18.9
0.05(42-y) + 0.65y = 18.9
2.1 - 0.05y + 0.65y = 18.9
0.6y = 18.9 - 2.1
0.6y = 16.8
y = 28 ml
Substitute with y in equation II to get x as follows:
x = 42-y
x = 42 - 28
x = 14 ml
Based on the above calculations:
amount of 5% solution = x = 14 ml
amount of 65% solution = y = 28 ml
The correct choice is:
The teacher will need 14 mL of the 5% solution and 28 mL of the 65% solution.
Answer:
2502.1
Step-by-step explanation:
4754/1.9
= 2,502.1
Hence the andwer is 2502.1
The area of Erin's circle to the nearest hundredth is 50.24 in².
<h3>What is the area of the circle?
</h3>
A circle is a bounded figure which points from its center to its circumference is equidistant.
Area of a circle = πr²
Where :
3.14 X 4²
(3.14) (4) (4) = 50.24 in²
To learn more about the area of a circle, please check: brainly.com/question/14351152
#SPJ1
Answer:
yEAH MAN
Step-by-step explanation:
no doubt
213+497=710 total students, so 213 wore a silly hat so that would be 30% wore the silly hats
