Answer:
252
Step-by-step explanation:
The order of the books isn't important, so we'll use combinations.
The number of ways to choose 5 books from 10 is:
₁₀C₅ = 10! / (5! (10 − 5)!)
₁₀C₅ = 10! / (5! 5!)
₁₀C₅ = 10×9×8×7×6 / (5×4×3×2×1)
₁₀C₅ = 252
The answer is 108°
A regular pentagon has all its five sides equal and all five angles are also equal. Hence, the measure of each interior angle of a regular pentagon is given by the below formula. Measure of each interior angle = [(n – 2) × 180°]/n = 540°/5 = 108°.
