The probability that you will guess the first answer correctly = 1/2 = 0.5
The probability that you will guess the second answer correctly = 1/2 = 0.5
The probability that you will guess the third answer correctly = 1/2 = 0.5
The probability that you will guess all three answers correctly is
(0.5) x (0.5) x (0.5) = 0.125 = 12.5% .
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Here are all the ways your answer sheet could wind up:
(R = a right answer. W = a wrong answer.)
W W W
W W R
W R W
W R R
R W W
R W R
R R W
R R R
Number of possible ways to score 0 right out of 3 questions: 1 way
Number of possible ways to score 1 right out of 3 questions: 3 ways
Number of possible ways to score 2 right out of 3 questions: 3 ways
Number of possible ways to score 3 right out of 3 questions: 1 way
Statistically, if your answers are all pure guesses,
then on the average, the score you expect is
(0 + 33-1/3 + 33-1/3 + 33-1/3 + 66-2/3 + 66-2/3 + 66-2/3 + 100) / 8
= 400 / 8
= 50% .
If you're happy with that score, great !
Go to the movies the night before the test,
and start guessing.
To find the average, add the cost of each book to get a total cost, then divide the total cost by the number of books purchased.
Total cost: 32 + 45 + 39 = 116
Average cost: 116 / 3 = 38.67
To answer this, we substitute 12 ft to the f(h) in the given equation,
f(h) = -8t² + 8t + 12 = 12
Subtracting 12 from both sides of the equation will give us an answer of,
-8t² + 8t = 0
Then, we transpose 8 to the other side and divide the equation by -8 and t, we get an answer of t = 1 second.
The question as presented is incomplete, here is the complete question with the multiple choice:
The sequence a1 = 6, an = 3an − 1 can also be
written as:
1) an = 6 ⋅ 3^n
2) an = 6 ⋅ 3^(n + 1)
3) an = 2 ⋅ 3^n
4) an = 2 ⋅ 3^(n + 1)
The correct choice is option 3) an = 2⋅3^n.
If we look at the initial sequence an = 3⋅an-1, and
a1 = 3⋅a0 = 6
a0 = 6/3
a0 = 2
We can now look at the sequence.
a0 = 2
a1 = 6
a2 = 18
a3 = 54
etc...
A common factor in each of those numbers is 2, so we can rewrite the sequence by factoring out 2.
a0 = 2⋅1
a1 = 2⋅3
a2 = 2⋅9
a3 = 2⋅27
The numbers being multiplied by 2 are all factors of 3. So we can rewrite the sequence again as:
a0 = 2⋅3^0
a1 = 2⋅3^1
a2 = 2⋅3^2
a3 = 2⋅3^3
This sequence can now be rewritten as an = 2⋅3^n.
