The University of Sydney
Faculty of Economics and Business  
MathQuiz  

Factorial Notation - Quiz 3   Last unanswered question  Question  Next unanswered question

Question 1 lion

Is the following statement True or False?
6! = 126.
a) True   b) False

 

Not correct. Choice (a) is false.
The statement is false
6! = 6× 5 ×4 × 3× 2× 1 = 720.
Your answer is correct.
The statement is false
6! = 6× 5 ×4 × 3× 2× 1 = 720.
Question 2 lion

Which of the following evaluates 5! correctly?
a) 5! = 15 .    b) 5! = 60.
c) 5! = 720.    d) 5! = 120.

 

Not correct. Choice (a) is false.
Try again, you have calculated 5 + 4 + 3 + 2 + 1 = 15.
Not correct. Choice (b) is false.
Try again, you have not calculated 5 × 4 × 3 × 2 × 1.
Not correct. Choice (c) is false.
Try again, this is 6!.
Your answer is correct.
5! = 5 × 4× 3× 2× 1 = 120.
Question 3 lion

Which of the following correctly evaluates 9!
4!.
a) 9!= 210 .
4!    b) 9!
4! = 90720.
c) 9!
4! = 15120.    d) 9!   9
4! = 4 .

 

Not correct. Choice (a) is false.
9!= 9× 8 × 7× 6× 5 /= 210.
4!
Not correct. Choice (b) is false.
Try again, this is 9!
4-.
Your answer is correct.
9!
4!-= 9× 8× 7 × 6× 5 = 15120.
Not correct. Choice (d) is false.
Try again, you have forgotten the factorials.
Question 4 lion

Which of the following is the correct evaluation of  7!
4!3!.
a)  7!
4!3! = 35.    b) 7!--
4!3! = 70.
c) -7!- = 420 .
4!3!    d) -7!-= -7 .
4!3!  12

 

Your answer is correct.
-7!-   7×-6×-5-
4!3! = 3× 2× 1 = 35.
Not correct. Choice (b) is false.
Try again, have you divided by 3! or by 3.
Not correct. Choice (c) is false.
Try again, you have calculated -7!--.
4× 3
Not correct. Choice (d) is false.
Try again, you have forgotten the factorial symbol.
Question 5 lion

Which of the following is the correct simplification of (n+-2)!
(n- 2)!  where n > 2 ?
a) (n-+-2)! = (n + 2)(n + 1)n(n - 1)(n - 2).
(n - 2)!
b) (n+-2)!
(n- 2)! = (n+ 2)(n+ 1)n(n- 1).
c) (n-+-2)!
(n - 2)! = (n + 2)(n + 1)n
d) (n-+-2)!
(n - 2)! = -1

 

Not correct. Choice (a) is false.
Not quite, try again, recalling that n! = n(n - 1)!,  that is 5! = 5× 4!.
Your answer is correct.
(n-+-2)!   (n+-2)(n+-1)n(n--1)(n--2)!
(n - 2)! =          (n - 2)!          = (n+ 2)(n+ 1)n(n- 1).
Not correct. Choice (c) is false.
Not quite, try again, recalling that n! = n(n- 1)!,  that is 5! = 5 × 4!.
Not correct. Choice (d) is false.
Try again, you cannot have negative numbers here.