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