Bunuel
What is the greatest integer, k, such that 5^k is a factor of the product of the integers from 1 through 24, inclusive?
A 1
B 2
C 3
D 4
E 5
We want to know how many times the prime number 5 appears in the prime factorization of the product 1 × 2 × 3 × ... × 24 (which is 24!). Every time a number in that range is divisible by 5, it contributes at least one factor of 5. Some numbers might contribute more than one factor if they are divisible by a higher power of 5.
Step 1: Count the numbers from 1 to 24 that are multiples of 5. These numbers are 5, 10, 15, and 20. That gives us 4 factors of 5.
Step 2: Check if any number in the range is a multiple of 25 (since 25 = 52 would contribute an extra factor of 5). In the range from 1 to 24, there are no numbers that are 25 or greater, so none of the numbers provide an extra factor.
So, in total, 5 appears 4 times in the factorization of 24!. This means the greatest integer k such that 5^k divides the product is 4.
The correct answer is 4 (option D).