Permutations and Combinations

1. In how many ways can three marbles be selected simultaneously from a box containing 12 different marbles?

A. 110  

B. 220  

C. 660  

D. 240 

 
Correct Answer : B
2. If ${}^{n}{{P}_{4}}={}^{n}{{P}_{5}}$, then n =

A. 7  

B. 8  

C. 6  

D. 5 

 
Correct Answer : D
3. Find the value of ${}^{8}{{P}_{3}}$

A. 166  

B. 336  

C. 672  

D. 536 

 
Correct Answer : B
4. If, ${}^{n}{{C}_{12}}={}^{n}{{C}_{18}}$, then find ${}^{n}{{C}_{3}}$

A. 4060  

B. 240  

C. 30  

D. 1140 

 
Correct Answer : A
5. Find the value of ${}^{10}{{C}_{7}}$

A. 60  

B. 360  

C. 120  

D. 720 

 
Correct Answer : C
6. Find the value of ${}^{12}{{C}_{2}}$

A. 55  

B. 66  

C. 132  

D. 110 

 
Correct Answer : B
7. If ${}^{n}{{{P}}_{r}}=990$ and ${}^{n}{{C}_{r}}=165$, then find the value of r.

A. 3  

B. 6  

C. 4  

D. 5 

 
Correct Answer : A
8. If ${}^{n}{{C}_{7}}={}^{n}{{C}_{3}}$ , then n =

A. 10  

B. 4  

C. 7  

D. 3 

 
Correct Answer : A
9. ${}^{8}{{C}_{7}}+{}^{8}{{C}_{6}}=$ (A)${}^{9}{{C}_{6}}$ (B) ${}^{8}{{C}_{7}}$ (C) ${}^{9}{{C}_{7}}$ (D)8

A. A  

B. B  

C. C  

D. D 

 
Correct Answer : C
10. The value of ${}^{240}{{C}_{239}}$

A. 1  

B. 240  

C. 239  

D. 0 

 
Correct Answer : B
11. Relation between ${}^{n}{{C}_{r}}$ and ${}^{n}{{\operatorname{P}}_{r}}$ is (A) ${}^{n}{{{P}}_{r}}$ = Â ${}^{n}{{C}_{r}}$ (B) ${}^{n}{{{P}}_{r}}$ =Â ${}^{n}{{C}_{n-r}}$ (C) ${}^{n}{{{P}}_{r}}$ = r! ${}^{n}{{C}_{r}}$ (D) ${}^{n}{{C}_{r}}$= r! x ${}^{n}{{{P

A. A  

B. B  

C. C  

D. D 

 
Correct Answer : C
12. In how many ways can 4 girls be seated on 10 different chairs in a row?

A. 3080  

B. 720  

C. 1080  

D. 5040 

 
Correct Answer : D
13. The number of different words that can be formed using all the letters of the word SPECIAL that begin with S and end with L is

A. 5!  

B. 7!  

C. 6!  

D. 4! 

 
Correct Answer : A
14. Number of ways of selecting 5 out of 7 persons is (A) ${}^{7}{{P}_{5}}$ (B) ${}^{7}{{C}_{5}}$ (C)7! (D)5!

A. A  

B. B  

C. C  

D. D 

 
Correct Answer : B
15. Number of ways of arranging 3 persons in 8 distinct chairs is (A) ${}^{8}{{P}_{3}}$ (B) ${}^{8}{{C}_{3}}$ (C)8! (D) 3!

A. A  

B. B  

C. C  

D. D 

 
Correct Answer : A
16. The number of ways of forming a garland using 21 different flowers is (A)20! (B)21! (C)21 (D)$\frac{20!}{2}$

A. A  

B. B  

C. C  

D. D 

 
Correct Answer : D
17. Number of even numbers can be formed using all the digits 1, 3, 5, 6, 7 is

A. 5!  

B. 5  

C. 4!  

D. 0 

 
Correct Answer : C
18. Number of odd numbers that can be formed using the digits 2, 4, 6, 8 is

A. 4!  

B. 4  

C. 1  

D. 0 

 
Correct Answer : D
19. Neha has 10 different chocolates. In how many ways can she give them to two of her friends?

A. 10!  

B. 2¹⁰  

C. 10  

D. 9 

 
Correct Answer : B
20. How many arrangements can be made by using all the letters of the word ‘‘COMPLEX"?

A. 720  

B. 5040  

C. 2520  

D. 40320 

 
Correct Answer : B
21. Find the number of ways of arranging ail the letters of the word ARRANGE. (A)7! (B) $\frac{7!}{{{\left( 2! \right)}^{2}}}$ (C)$\frac{7!}{2!}$ (D)4! 7!

A. A  

B. B  

C. C  

D. D 

 
Correct Answer : B
22. The number of diagonals in a regular decagon is

A. 35  

B. 45  

C. 40  

D. 50 

 
Correct Answer : A
23. In how many ways can 6 letters be posted into 4 letterboxes? (A)${{6}^{4}}$ (B)${}^{6}{{P}_{4}}$ (C) ${{4}^{6}}$ (D) ${}^{6}{{C}_{4}}$

A. A  

B. B  

C. C  

D. D 

 
Correct Answer : C
24. A set has 8 elements. How many non-empty subsets are there for the sot?

A. 256  

B. 8  

C. 255  

D. 7 

 
Correct Answer : C
25. In how many ways can we select two vertices in a hexagon?

A. 12  

B. 10  

C. 15  

D. 16 

 
Correct Answer : C
26. In a library there are 10 research scholars. In how many ways can we select 4 of them?

A. 200  

B. 210  

C. 160  

D. 180 

 
Correct Answer : B
27. In how many ways can 6 persons be seated around a circular table?

A. 720  

B. 120  

C. 24  

D. 60 

 
Correct Answer : B
28. Find the number of diagonals in a regular octagon.

A. 16  

B. 20  

C. 18  

D. 12 

 
Correct Answer : B
29. Find the number of ways in which 8 delegates can be arranged around a table for a meeting.

A. 420  

B. 360  

C. 600  

D. 840 

 
Correct Answer : D
30. Number of ways of arranging 5 persons in a row is

A. 5  

B. 10  

C. 5!  

D. 20 

 
Correct Answer : C

No comments:

Post a Comment