Answer: 18L
Explanation:
Solving this question would be easier by assigning variables.
so, let x = amount of 67% needed solution
Let y = amount of 42% needed solution.
From the question, we know that
x + y = 42 thus,
y = 42 - x
we also know that the pure herbicide in the 67% solution plus the herbicide I'm the 46% solution must be equal to the amount of pure herbicide in the final solution. Thus mathematically, we have
0.67x + 0.46y = 0.55*42
0.67x + 0.46y = 23.1
Remember, y = 42 - x, substituting this value, we have
0.67x + 0.46(42-x) = 23.1
0.67x + 19.32 - 0.46x = 23.1
0.21x = 23.1 - 19.32
0.21x = 3.78
x = 18
.therefore the amount of 67% solution needed is 18L
The answer is D. The energy can not be created or destroyed. It can only be transformed from one form to another. This is called the law of conservation of energy. So the word "make" and "create" is not correct.
Answer: A=1, B=3, C=12
Explanation:
For this problem, you will need to know your unit conversions. There are 3 ft in 1 yard. Knowing this, we can find A, B, C.
For A and B, we know that we want to cancel out ft so the answer can be in yards. To do so, we need to put B=3 and A=1.
Now that we know the unit conversion, we can directly solve.
36 ft×(1 yd/3 ft)=12 yd
Our final answer is A=1, B=3, C=12.
