1. factorial form of $n(n^2-1)=?$
2. The value of $n$ when $^{11}P_n = 11 \cdot 10 \cdot 9$ is:
3. If $r=n$, ${}^nC_r$ is equal to ________
4. Let $A=\{1,2,3,...,20\}$ Find the number of ways that the integer chosen is a prime number.
5. ${}^nC_r \times r!$=________?
6. If $n$ is a negative integer then $n!$ is
7. If ${}^nC_4={}^nC_{10}$ then value of $n$ is;
8. $^nP_r$ is equal to (where $n > 0$, $r > 0$):
9. Number of words that can be formed from the letters of the word "PLANE'' using all letters at a time is equal to:
10. ${}^nC_r + {}^nC_{r-1}=?$
11. Number of ways of arrangements of the word $\textbf{GARDEN}$
12. $n$ different objects taken all at a time can be arranged in:
14. The value of $4! \cdot 0! \cdot 1!$ is
15. The factorial form of $\frac{10.9}{2.1}$ is
16. If $^nC_5 = ^nC_4$, then $n$ is equal to:
17. 5 persons can be seated at a round table in how many ways?
18. Factorial form $\frac{(n+1)(n)(n - 1)}{3 \cdot 2 \cdot 1}$ is
19. Factorial form of $n(n - 1)(n - 2) = ?$
20. The expression $\frac{(n - 1)!(n - 2)!}{(n!)^2}$ reduced to
21. $\frac{^nP_r}{r!}$ is equal to:
22. Number of ways of arranging 5 keys in a circular ring is:
23. The number of permutations of the word "ANAMA" is:
24. If $n$ is a positive integer, then factorial of $n$ is denoted by ---
25. If $^nC_r = ^nC_q$, which of the following must be true:
26. $\frac{n!}{r!(n-r)!}$ is equal to:
27. ${}^nC_r$ is valid only if
28. The total number of 6-digit numbers in which all the odd and only odd digit appear is
29. Factorial notation was introduced by
30. The value of $\frac{4!}{0!}$ is
31. The product of r consecutive positive numbers in divisible by:
32. If $3{}^nP_3={}^nP_4$ then value of n is:
33. If $r = n$, then $^nP_r$ equals:
34. From $A=\{1,3,5,7,9\}$ and $B=\{2,4,6,8\}$ if a Cartesian product $A \times B$ is chosen, then number of ways that $a+b=9$;
35. The value of permutation $^{20}P_3$ is:
36. A student has to answer 10 out of 12 questions in an examination such that he must be choose at least 4 from first 5 questions. The nature of choice is:
37. $(n - 1)(n - 2)(n - 3) \ldots (n - r + 1) = ?$
38. ${}^nC_{n-r}$ is equal to:
39. Circular permutation of $n$ non-living things is given by:
40. If ${}^{15}C_{3r}={}^{15}C_{r+3}$ then value of $r$ is:
41. The value of $n$ if $^nC_{10} = \frac{12 \times 11}{2!}$:
43. The number of ways in which $r$ letters can be posted in n-letter boxes in a town in;
44. In how many ways a cricket team of 11 players out of 15 can be selected if the captain must be included in each way:
45. ${}^nC_{r}={}^nC_{n-r}$ is useful when
