Question
find the permutation and combination of the
word “EXAMINATION” taking 4ata time.
word “EXAMINATION” taking 4ata time.
Ask by Reed Ortega. in Nepal
Mar 25,2025
Upstudy AI Solution
Tutor-Verified Answer
Answer
There are 330 ways to choose 4 letters from “EXAMINATION” (combinations) and 7,920 ways to arrange those 4 letters (permutations).
Solution
To find the permutations and combinations of the word “EXAMINATION” taking 4 letters at a time, we first need to analyze the letters in the word.
The word “EXAMINATION” consists of 11 letters, with the following frequency of letters:
- E: 1
- X: 1
- A: 1
- M: 1
- I: 2
- N: 2
- T: 1
- O: 1
Step 1: Calculate Combinations
The number of combinations of selecting 4 letters from the 11 letters can be calculated using the formula for combinations:
Where:
-
is the total number of items (letters), -
is the number of items to choose.
Step 2: Calculate Permutations
The number of permutations of selecting 4 letters from the 11 letters can be calculated using the formula for permutations:
Step 3: Calculate Both Values
Let’s calculate both the combinations and permutations for the word “EXAMINATION” taking 4 letters at a time.
- Combinations:
- Permutations:
Now, I will compute these values.
Solve the equation by following steps:
Solve the equation by following steps:
- step0: Solve for
:
- step1: Reorder the terms:
- step2: Divide both sides:
- step3: Divide the numbers:
Solve the equation.
Solve the equation by following steps: - step0: Solve for
:
- step1: Reorder the terms:
- step2: Divide both sides:
- step3: Divide the numbers:
The calculations for the combinations and permutations of the word “EXAMINATION” taking 4 letters at a time are as follows:
-
Combinations:
-
Permutations:
However, since combinations and permutations must be whole numbers, let’s compute the exact values for
and
again without the fractions.
Exact Calculations
-
Combinations:
-
Permutations:
Now, I will compute these values accurately.
Calculate the value by following steps:
Calculate the value by following steps:
- step0: Calculate:
- step1: Multiply the terms:
- step2: Multiply the numbers:
Calculate or simplify the expression.
Calculate the value by following steps: - step0: Calculate:
- step1: Multiply the terms:
- step2: Multiply the terms:
- step3: Reduce the fraction:
The exact calculations for the combinations and permutations of the word “EXAMINATION” taking 4 letters at a time are:
-
Combinations:
-
Permutations:
Thus, the number of ways to choose 4 letters from “EXAMINATION” is 330 (combinations), and the number of ways to arrange those 4 letters is 7920 (permutations).
Answered by UpStudy AI and reviewed by a Professional Tutor
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The Deep Dive
To find the number of ways to arrange “EXAMINATION” taking 4 letters at a time, we first notice that the word has 11 letters with the letter ‘I’ appearing twice. For permutations, we have two scenarios: choosing 4 different letters or including the repeated letter.
-
First, count the distinct letters in “EXAMINATION”: E, X, A, M, I (×2), N, T, O. That’s 8 distinct letters.
-
If we choose 4 different letters from these 8, the number of arrangements (permutations) would be calculated as
. -
If we choose the letter ‘I’ twice and two other distinct letters, the formula changes. Suppose we select 2 more letters from the 7 remaining distinct letters. The count for this scenario is
arrangements of ‘I’, so it becomes .
In total, we get
total arrangements.
Now, you’ve got a fun mix of math and letters, making “EXAMINATION” quite the lexical playground!