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.
Answer: 9
because you need to first use the ones in the parentheses and then move on.
The rate Ritz can eat apples is 8/15 apples per minute.
Set the rate (which is measured apples / minutes) equal to 16 apples / t minutes.
(8/15) = (16/t)
Cross multiply.
16*15 = 8t
t = 20
The answer is 30 minutes. You could solve the problem with basic reasoning as well. 16 is twice the number of apples as 8, so the time it takes to eat them will be double 15 minutes.
Answer:
$22 for popcorn and $8 for pretzels together it would be $30
Step-by-step explanation: