A. To find the multiples of 5 or 3 from 5 to 25, we must find the multiples of 5 and the multiples of 3, and remove duplicates (15 and 20). The multiples of 5 are: 5, 10, 15, 20, and 25. The multiples of 3 are: 6, 9, 12, 15, 18, 21, and 24. So, the numbers that are multiples of 5 or 3 are: 5, 6, 9, 10, 12, 15, 18, 20, 21, 24, making a total of 10 numbers. Therefore, the probability is:
P(multiple of 5 or 3) = 10/21
B. To find the even or prime numbers, we must identify which numbers are even and which ones are prime. The even numbers are: 6, 8, 10, 12, 14, 16, 18, 20, 22, 24. The prime numbers are: 5, 7, 11, 13, 17, 19, 23. So, the even or prime numbers are: 5, 6, 7, 10, 11, 12, 13, 14, 16, 17, 18, 19, 20, 22, 23, and 24, making a total of 16 numbers. Therefore, the probability is:
P(even or prime) = 16/21
C. To find the numbers that are less than or greater than 18, we just need to count them. The numbers less than or equal to 18 are: 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, and 18, making a total of 14 numbers. The numbers greater than 18 are: 19, 20, 21, 22, 23, and 24, making a total of 6 numbers. Therefore, the probability of choosing a number less than or greater than 18 is:
P(less or greater than 18) = 20/21
If a number is chosen at random from the integers 5 to 25 inclusive, find the probability that the number is
A.multiple of 5 or 3
B.even or prime number
C.less or greater than 18
1 answer