Question

17. Evaluate a. 6! b. 8P5 c. 12C4

Answer 1

the factorial ! just means we multiply by every natural number less that the value so
6! =6×5×4×3×2×1= 720

for permutations we use the formula n!/(n-r)!
so we have 8!/(8-5)!=8!/3!=8×7×6×5×4

for combinations s we have n!/(n-r)!r!
so we have 12!/(12-4)!4!=12!/8!4!=12×11×10×9/4×3×2=11×10×9/2=99×5