Answer:
33 1/3 L of the 40% solution, 16 2/3 L of the 25% solution
Step-by-step explanation:
Set up two equations...
Let x represent the number of Liters of the 40% solution
Let y represent the number of Liters of the 25% solution
We need 50 liters total, so
x + y = 50
and we need the 50 L to be 35% solution, so
0.4x = 0.25y = 0.35(50)
Solve the first equation for one variable...
x = 50 - y (subtract y from both sides in equation 1)
Now substitute that value into the second equation...
0.4(50 - y) + 0.25y = 17.5 (x becomes 50 - y, 0.35(50) = 17.5)
Now solve for y...
20 - 0.4y + 0.25y = 17.5
-0.15y = -2.5
y = 16.66666667
y = 16 2/3 L
So we need to plug that into the first equation to find 'x'
x + 16 2/3 = 50
x = 50 - 16 2/3
x = 33 1/3
Answer:
z=35.1
Step-by-step explanation:
Answer: -7
Step-by-step explanation: The sea level is at 0 so 0-7= -7
The language art teacher wants to know the opinion of the ENTIRE school, so it would be fair if the teacher takes a sample from the ENTIRE school population. She can use the stratified sampling method where she can take a proportionate sample from each grade.
Correct answer: All students in each grade
