Answer: there are 10 multiple choice questions and 15 short-answer questions
Step-by-step explanation:
Let x represent the number of multiple choice questions in the test.
Let y represent the number of short-answer questions in the test.
If the test has 25 questions, it means that
x + y = 25
Multiple-choice questions are worth 2 points, and short-answer questions are worth 4 points. The test is worth a total of 80 points. It means that
2x + 4y = 80 - - - - - - - -1
Substituting x = 25 - y into equation 1, it becomes
2(25 - y) + 4y = 80
50 - 2y + 4y = 80
- 2y + 4y = 80 - 50
2y = 30
y = 30/2 = 15
x = 25 - y = 25 - 15 = 10
A. The number of multiple-choice questions plus the number of short-answer questions is 25.
<h3>
Answer: 90720 </h3>
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Explanation:
There are 9 letters in "Metallica", so there would be 9! = 9*8*7*6*5*4*3*2*1 = 362880 different permutations; however, this is only the case if we could tell the letters L and A apart.
We have two copies of each of those repeated letters, so we have to divide by 2!*2! = (2*1)*(2*1) = 4 to account for these repeats.
Because we can't tell the repeated letters apart, we really have (9!)/(2!*2!) = (362880)/(4) = 90720 different permutations.
Hello from MrBillDoesMath!
Answer:
The fourth choice, b = +\- sqrt( sg + a^2)
Discussion:
s = (b^2 - a^2)/g => multiply both sides by "g"
sg = b^2 - a^2 => add a^2 to both sides
sg + a^2 = b^2 => take the square root of each side
b = +\- sqrt( sg + a^2)
which is the fourth choice.
Thank you,
MrB
Answer:
y = 18 / (x + 2)²
Step-by-step explanation:
Inversely proportional
y * (x + 2)² = k
when x=1, y=2
k = 2 * (1 + 2)²
k = 18
-----------------------
y * (x + 2)² = 18
Divide both sides by (x + 2)²
y = 18 / (x + 2)²
I believe the second one, double check
