Find the probability of a number picked at random from the numbers 1 through 15 that is prime.
The prime numbers between 1 and 15 are: 2, 3, 5, 7, 11, and 13. There are 6 prime numbers out of a total of 15 numbers, so the probability is:
$$ \frac{6}{15}=\boxed{\frac{2}{5}} $$
To find the probability of a number picked at random from the numbers 1 through 15 that is prime, we need to determine the number of prime numbers between 1 and 15 and divide it by the total number of numbers in that range. Here's how you can calculate it step by step:
Step 1: Determine the prime numbers between 1 and 15.
The prime numbers between 1 and 15 are: 2, 3, 5, 7, 11, 13.
Step 2: Count the number of prime numbers.
There are 6 prime numbers between 1 and 15.
Step 3: Determine the total number of numbers between 1 and 15.
There are 15 numbers between 1 and 15.
Step 4: Calculate the probability.
The probability of picking a prime number from the numbers 1 through 15 is given by the ratio of the number of prime numbers to the total number of numbers:
Probability = (Number of prime numbers) / (Total number of numbers)
Probability = 6/15
Probability = 2/5
So, the probability of picking a prime number at random from the numbers 1 through 15 is 2/5 or 40%.