To solve this problem, we can use the combination formula:
nCr = n! / r!(n-r)!
where n is the total number of items, r is the number of items to choose, and ! denotes factorial (the product of all positive integers up to that number).
In this case, n = 6 (the total number of books available) and r = 4 (the number of books Beth can choose). Using the formula:
6C4 = 6! / 4!(6-4)!
6C4 = 6! / 4!2!
6C4 = (6 x 5 x 4 x 3) / (4 x 3 x 2 x 2)
6C4 = 15
Therefore, there are 15 different combinations of four books that Beth could choose from those six.
Beth’s mother told her that she can choose four books from the book fair. There are six books now Beth would like to have. How many different combinations of four books could Beth choose from those six?
1 answer