750 times
Explanation:
Since you are 5 times as likely to roll a composite number as a prime number, the probability of rolling a composite number is 5/6 and the probability of rolling a prime number is 1/6.
If a prime number appeared 185 times, that means that a prime number has a probability of 185/(185+x), where x is the number of times a composite number appears.
Therefore, (185/(185+x)) = 1/6
185 = (185+x)/6
1110 = 185 + x
x = 925
So, you should expect a composite number to appear 925 times. As there are 6 numbers in the sample space total, the number of composite numbers should be 925 - 6 = 750 times.
The sample space for a number cube is {3, 6, 9, 12, 15, 18}.
You are 5 times as likely to roll a composite number as a prime number on 1 roll of the cube. If the cube is rolled multiple times and a prime number appears 185 times, how many composite numbers should you expect to appear?
825 times
725 times
750 times
925 times
1 answer
1 answer