Here are the solutions for Exercise 2:
Exercise 2: How many ways can you arrange 3 French books, 2 history books, and 5 maths books?
Total number of books = 3 (French) + 2 (History) + 5 (Maths) = 10 books.
a) All books are different
Step 1: Determine the total number of books.
N=3+2+5=10
Step 2: If all books are different, then arranging them is a permutation of N distinct items. The number of ways is N!.
Numberofways=10!
Step 3: Calculate the factorial.
10!=10×9×8×7×6×5×4×3×2×1=3,628,800
The number of ways to arrange the books if all books are different is 3,628,800.
b) All the French books look the same, all the history books look the same and all the maths books look the same.
Step 1: Identify the total number of books (N) and the number of identical books in each category.
N=10
Number of French books (nF) = 3
Number of History books (nH) = 2
Number of Math books (nM) = 5
Step 2: Use the formula for permutations with repetitions:
Numberofways=nF!nH!nM!N!
Step 3: Substitute the values and calculate.
Numberofways=3!2!5!10!
Numberofways=(3×2×1)×(2×1)×5!10×9×8×7×6×5!
Numberofways=3×2×1×2×110×9×8×7×6
Numberofways=1230240
Numberofways=2520
The number of ways to arrange the books with identical books in each category is 2520.