Exercise 7.2
Q1. Evaluate: (i) 8!
Solution:
(i) 8! = 1 × 2 × 3 × 4 × 5 × 6 × 7 × 8 = 40320
(ii) 4! - 3!
Solution:
(ii) 4! = 1 × 2 × 3 × 4 = 24
3! = 1 × 2 × 3 = 6
∴ 4! – 3! = 24 – 6 = 18
Q2. Is 3! + 4! = 7!?
Solution: 3! = 1 × 2 × 3 = 6
4! = 1 × 2 × 3 × 4 = 24
3! + 4! = 6 + 24 = 30
7! = 1 × 2 × 3 × 4 × 5 × 6 × 7 = 5040
∴ 3! + 4! ≠ 7!
