There are 18 number-tiles in a jar, each marked with a different number from 1-18. If you pull out one tile at random, what is the probability that the number you pull will be an even number or a prime number?
Responses
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0.944
0.944 - no response given
0.722
0.722 - no response given
0.833
0.833 - incorrect
0.889
To find the probability that the number you pull will be an even number or a prime number, we first need to count the total number of even numbers and prime numbers between 1 and 18.
Even numbers between 1 and 18: 2, 4, 6, 8, 10, 12, 14, 16, 18 (9 numbers)
Prime numbers between 1 and 18: 2, 3, 5, 7, 11, 13, 17 (7 numbers)
However, we have counted 2 twice because it is both even and prime, so we need to subtract it once.
Total = 9 (even numbers) + 7 (prime numbers) - 1 (2 is counted twice) = 15 numbers
Therefore, the probability of pulling out an even number or a prime number is:
Probability = (Total favorable outcomes) / (Total possible outcomes) = 15 / 18 = 0.833
So the correct response is 0.833.