Permutations and Combinations Quiz Set 013

Advertisement


Your Score
Correct Answers:
Wrong Answers:
Unattempted:

Question 1

What is the value of 7C2?

 A

21.

 B

31.

 C

11.

 D

41.

Soln.
Ans: a

7C2 is ${7 !}/{(7 - 2) ! × 2 !}$ = 21.


Question 2

How many possible outcomes are there if a die with 5 faces is cast and then a coin with 2 sides is tossed?

 A

10.

 B

15.

 C

8.

 D

11.

Soln.
Ans: a

The die can fall in 5 different ways, and a coin in 2 ways. So the outcomes are 2 × 5 = 10.


Question 3

How many 5 digit numbers ending in 0 can be formed with a given set of 7 distinct digits none of which is 0? Repetition of digits is not allowed.

 A

840.

 B

850.

 C

870.

 D

860.

Soln.
Ans: a

The units place is blocked by zero. The tens place has 7 options, the hundreds place also has (7 - 1) options, and so on. This is expressed as 7 × 6 × 5 × 4 × 1, which evaluates to 840.


Question 4

Out of given 4 consonants and 3 vowels, how many words can be formed that contain 3 consonants and 2 vowels or 2 vowels and 3 consonants?

 A

2160.

 B

2170.

 C

2150.

 D

2180.

Soln.
Ans: a

We can make the selection in 3C3 × 4C2 + 3C2 × 4C3 ways. But the five members can themselves be arranged in 5! ways. So the number of words is 120 × (3C3 × 4C2 + 3C2 × 4C3) = 2160.


Question 5

How many 6 digit numbers ending in 0 can be formed with a given set of 8 distinct digits none of which is 0? Repetition of digits is not allowed.

 A

6720.

 B

6730.

 C

6750.

 D

6740.

Soln.
Ans: a

The units place is blocked by zero. The tens place has 8 options, the hundreds place also has (8 - 1) options, and so on. This is expressed as 8 × 7 × 6 × 5 × 4 × 1, which evaluates to 6720.


buy aptitude video tutorials


Creative Commons License
This Blog Post/Article "Permutations and Combinations Quiz Set 013" by Parveen (Hoven) is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Updated on 2017-04-07.

Posted by Parveen(Hoven),
Aptitude Trainer


Advertisement