Evaluate the expression without using a calculator. 6! 4!(6 - 4)! The answer is (Type an integer or a simplified fraction.)n! n! For the given values of n and r, evaluate (a) and (b) for n = 12 and r - 5. (n - r)! r!(n - r)! n! (a) When n = 12 and r = 5, (n - r) ! (Simplify your answer. Type an integer or a simplified fraction.)\fEvaluate the expression using a calculator, 10! 10! = (Simplify your answer. Type an integer or a fraction.)n! n! For the given values of n and r, evaluate (a) (n - r)! and (b) for n = 18 and r = 3. r!(n - r)! (a) When n = 18 and r = 3, n! (n - r)! (Simplify your answer.)\f\fEvaluate the expression without using a calculator. 50! 48! . 2! 50! 48! - 2! (Simplify your answer. Type an integer or a simplified fraction.)Complete the statement with the correct numerical response. The value of 0! is The value of 0! isEvaluate the expression. 18! 14!4! 18! 14!4! (Simplify your answer. Type an integer or a fraction.)