Suppose you have 10 marbles, They are marked with the numbers: 1,2,3,4,5,6,7,8,9 or 10. They are placed in a jar and you reach in and select one. What is the probability that the number you select has a factor of 3?. What is the probability that the number you select is a prime number?. Even number?. Evenly divisible by 13?.

Factor of 3 = 3/10

Prime = 1/2

Even = 1/2

Evenly divisible by 13 = no chance

Total number of marbles = 10

Total number of marbles that has a factor of 3 = 3

They are {3, 6, 9)

P (factor of 3) = 3/10

Total number of marbles that is a prime number = 4

They are {2, 3, 5, 7}

P (Prime Number) = 4/10 = 2/5

Total number of marbles that is even: 5

They are {2, 4, 6, 8, 10}

P (even) = 5/10 = 1/2

Total number of marbles that is divisible by 13 = 0

P (divisible by 13) = 0/10 = 0