Answer:
18 L
Step-by-step explanation:
Given : she must mix a solution of 67% herbicide with a solution of 46% herbicide to form 42 liters of a 55% solution.
To Find: How much of the 67% solution must she use?
Let x = amount of 67% solution needed
Then 42-x=amount of 46% solution needed
Now we know that the pure herbicide in the 67% solution
So, pure herbicide = (0.67x)
The amount of pure herbicide in the 46% solution (0.46(42-x))
Now 42 liters of a 55% solution = (0.46(42-x))
So,
Amount of 67% solution + Amount of 46% solution = 42 liters of a 55% solution
⇒0.67x+0.46(42-x)=0.55*42
⇒0.67x+19.32-0.46x=23.1
⇒0.21x=3.78
⇒
⇒x = 18 liters
Hence she use 18 liters of the 67% solution
Assuming that the order of selection is not important, this is a question of number of ways. In other words, the combination should be computed. That is,
Number of ways of selection 5 flowers = 12C5 = 12!/{5!*(12-5)!} = 12!/{5!*7!} = 792
Therefore, there are 792 ways in which 5 flowers can be selected from the available 12 flowers.
A number times 1 always equals itself, so: 4×1 = 4, OR 2×2 = 4
What do we know about those two lines?
They are perpendicular, meaning they have the same slope.
We know the slope of both is not zero (neither is vertical).
Therefore either
1) Both slopes are positive and therefore the product is positive
2) Both slopes are negative and therefore the product is positive (minus by a minus is a plus)
For the y intercepts, we know that the line P passes through the origin.
Therefore its Y intercept is zero.
[draw it if this is not obvious and ask where does it cross the y axis]
Therefore the Y intercept of line K and line P is zero.
[anything multiplied by a zero is a zero]
So we know that the product of slopes is positive, and we know that the product of Y intercepts is zero.
So the product of slopes must be greater.
Answer A
