1. $\frac{10!}{12!} = \frac{1}{132}$
2. $\frac{8!}{6!} = 56$
3. $1! \cdot 2! = 2$
4. $\frac{3! \cdot 4!}{4!} = 6$
5. $\frac{(n-2)!}{(n-1)!} = \frac{1}{n-1}$
6. $(9!)^3 = 362880^3$
7. $\frac{n!(n-1)!}{(n+1)!(n-2)!} = \frac{n-1}{n+1}$
8. $\frac{n!}{(n+2)!} = \frac{1}{(n+1)(n+2)}$
9. $\frac{n!(n-1)!}{(n+1)!(n-2)!} = \frac{n-1}{n+1}$
10. $\frac{(n-2)!}{(n+1)!} = \frac{1}{(n+1)n(n-1)}$
11. $(10 \cdot 9 \cdot 8 \cdot 7) = 5040$
12. $95 \cdot 92 \cdot 91 = 797660$
13. $19 \cdot 18 \cdot 17 \cdot 16 \cdot 15 \cdot 14 \cdot 13 = 171531360$
14. $85 \cdot 84 \cdot 83 = 592620$
15. $20 \cdot 19 \cdot 18 \cdot 9 \cdot 8 \cdot 7 = 2571840$
16. $16 \cdot 15 \cdot 14 \cdot 49 \cdot 48 = 11854080$
17. $\frac{50 \cdot 49 \cdot 48 \cdot 47}{5!} = 2118760$
18. $\frac{63 \cdot 62 \cdot 61}{10 \cdot 9 \cdot 8} = \frac{238266}{720} = \frac{13237}{40}$
19. $\frac{100 \cdot 99 \cdot 98}{1 \cdot 2 \cdot 3} = 161700$
20. $\frac{16 \cdot 15 \cdot 14 \cdot 13}{200} = \frac{43680}{200} = 218.4$
Parent Tip: Review the logic above to help your child master the concept of factorial worksheet.
