20! / 16! = a 24 b 11,628 c 116,280 d a number too big to compute

Hi, can anyone show me how to do this problem? 100 points for this. in advance

Anature center offer 2 guided walks. the morning walk is 2/3 miles. the evening walk is 3/6 mile. which is shorter

(c) the diagram shows the first three shapes of a matchsticks arrangement.first shape = 3second shape = 5third shape = 7given m represents the number of matchstick used to arrange the n'th shape.(i) write a formula to represent the relation between m and n. express m as the subjectof the formula.(ii) 19 matchsticks are used to make the p'th shape. find the value of p.