.
Question 1.
    By the definition,  n! = 1 * 2 * 3 * 4 * . . . * n.
    So,  4! = 1*2*3*4.
    You can compute it on your own.
Question 2.
        
 = 
    this product 1*2*3*4*5 is in the numerator and in the denominator.
    So we can cancel it in the numerator and in the denominator.
    You will get then
        
 = 
,
    which is just much easier to calculate.
    So,  --YOU-- calculate it by hand OR using your calculator.
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At this point,  I complete my explanations.