Permutations And Combinations CBSE Questions & Answers

Permutations And Combinations

This is Mathematics Class 11 Permutations and Combinations CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
The number of ways in which 6 “ + “ and 4 “ – “ signs can be arranged in a line such that no two “ – “ signs occur together is
  • A
    C(10,4)
  • B
    a)C(7,4)
    Correct
  • C
    P(10,4)
  • D
    none of these
2
On a railway track, there are 20 stations. The number of tickets required in order that it may be possible to book a passenger from every station to every other is
  • A
    none of these
  • B
    C(20,2)
  • C
    400
  • D
    P(20,2)
    Correct
3
A class is composed 2 brothers and 6 other boys. In how many ways can all the boys be seated at the round table so that the 2 brothers are not seated besides each other?
  • A
    3600
    Correct
  • B
    720
  • C
    4320
  • D
    1440
4
The number of all selections which a student can make for answering one or more questions out of 8 given questions in a paper, when each question has an alternative, is:
  • A
    6561
  • B
    6560
    Correct
  • C
    255
  • D
    256
5
The number of ways in which 8 different flowers can be strung to form a garland so that 4 particular flowers are never separated is
  • A
    \({\text{4}}!.4!\)
  • B
    288
    Correct
  • C
    none of these
  • D
    \({\text{5}}!.4!\)
6
Different calendars for the month of February are made so as to serve for all the coming years. The number of such calendars is
  • A
    14
    Correct
  • B
    8
  • C
    2
  • D
    7
7
The number of all odd divisors of 3600 is
  • A
    45
  • B
    9
    Correct
  • C
    18
  • D
    none of these
8
The number of all even divisors of 1600 is
  • A
    none of these
  • B
    21
  • C
    3
  • D
    18
    Correct
9
A convex polygon of n sides has n diagonals. The value of n is
  • A
    5
    Correct
  • B
    6
  • C
    8
  • D
    7
10
The number of all possible positive integral solutions of the equation xyz = 30 is
  • A
    27
    Correct
  • B
    25
  • C
    none of these
  • D
    26
11
Number of all 4 digit numbers with distinct digits is
  • A
    \({}^9{P_3}\)
  • B
    9999
  • C
    \(9 \times {}^9{P_3}\)
    Correct
  • D
    none of these
12
The number of ways, in which a student can choose 5 courses out of 8 courses, when 2 courses are compulsory, is
  • A
    C(6,3)
    Correct
  • B
    none of these
  • C
    P(6,3)
  • D
    \({6^3}\)
13
The number of ways, in which a student can select one or more questions out of 12 each having an alternative, is
  • A
    \({3^{12}} - 1\)
    Correct
  • B
    \({2^{12}}\)
  • C
    \({3^{12}}\)
  • D
    \({3^{12}} + 1\)
14
20 students can compete for a race. The number of ways in which they can win the first three places is (given that no two students finish in the same place)
  • A
    1140
  • B
    none of these.
  • C
    6840
    Correct
  • D
    8000
15
The number of ways of dividing 52 cards equally into 4 sets is
  • A
    \({{52!} \over {{{\left( {13!} \right)}^4}}}\)
  • B
    none of these
  • C
    \({{52!} \over {4{{\left( {13!} \right)}^4}}}\)
  • D
    \({{52!} \over {4!{{\left( {13!} \right)}^4}}}\)
    Correct