How many ways can a committee of 4 be formed from 8 people? (2019)

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Q: How many ways can a committee of 4 be formed from 8 people? (2019)

Solution: The number of ways to form a committee of 4 from 8 is 8C4 = 70.

Steps: 10

Step 1: Understand that we need to choose 4 people from a group of 8 people.
Step 2: Recognize that the order in which we choose the people does not matter (i.e., choosing person A, B, C, D is the same as choosing D, C, B, A).
Step 3: Use the combination formula, which is written as nCr, where n is the total number of people and r is the number of people to choose. Here, n = 8 and r = 4.
Step 4: The combination formula is nCr = n! / (r! * (n - r)!), where '!' denotes factorial (the product of all positive integers up to that number).
Step 5: Calculate 8C4 using the formula: 8C4 = 8! / (4! * (8 - 4)!) = 8! / (4! * 4!).
Step 6: Calculate the factorials: 8! = 40320, 4! = 24, and (8 - 4)! = 4! = 24.
Step 7: Substitute the factorials into the formula: 8C4 = 40320 / (24 * 24).
Step 8: Calculate 24 * 24 = 576.
Step 9: Now divide 40320 by 576: 40320 / 576 = 70.
Step 10: Conclude that there are 70 different ways to form a committee of 4 from 8 people.