Question:
In how many ways can you select 4 letters from the word "mississippi"?

Answer:
To find the number of ways to select 4 letters from the word "mississippi," we need to consider the number of ways we can make selections while following the given rules.

Analysis:
The word "mississippi" consists of 11 letters, including 4 "i"s and 4 "s"s, and a single "m" and "p". We need to determine the number of ways we can select 4 letters from these 11 letters.

Solution:
We can solve this problem using combinations, which represent the number of ways to choose a subset of items without considering the order.

Step 1: Calculate the total number of letters:
The word "mississippi" has a total of 11 letters.

Step 2: Calculate the number of ways to select 4 letters:
To calculate the number of ways to select 4 letters, we use the combination formula:

C(n, r) = n! / (r! * (n-r)!)

Where n is the total number of items and r is the number of items we want to select.

In this case, we want to select 4 letters from a total of 11 letters. So, using the combination formula:

C(11, 4) = 11! / (4! * (11-4)!)
= 11! / (4! * 7!)

Step 3: Simplify the expression:
To simplify the expression, we need to calculate the factorials:

11! = 11 * 10 * 9 * 8 * 7 * 6 * 5 * 4 * 3 * 2 * 1
4! = 4 * 3 * 2 * 1
7! = 7 * 6 * 5 * 4 * 3 * 2 * 1

Substituting these values into the formula, we get:

C(11, 4) = (11 * 10 * 9 * 8 * 7 * 6 * 5 * 4 * 3 * 2 * 1) / ((4 * 3 * 2 * 1) * (7 * 6 * 5 * 4 * 3 * 2 * 1))

Step 4: Cancel out common factors:
We can cancel out common factors in the numerator and denominator:

C(11, 4) = (11 * 10 * 9 * 8) / (4 * 3 * 2 * 1)
= 330

Therefore, there are 330 ways to select 4 letters from the word "mississippi" while following the given rules.

Conclusion:
In conclusion, there are 330 ways to select 4 letters from the word "mississippi" while following the given rules.