ECAT Pre Engineering Mathematic MCQ Test With Answer for Chapter 9 (Permutation, Combination and Probability)

The number of permutations of n objects of which there are n₁like of one kind, n₂like of the second kind and n₃like objects of third kind are

• 
  A
• 
  B
• 
  C
• 
  D

(n + 2) (n + 1)n in factorial form is

• 
  A
• 
  B
• 
  C
• 
  D

n(n - 1) (n - 2) .... (n - r + 1) = ______

• 
  A
• 
  B
• 
  C
• 
  D

20. 19. 18. 17= _______

• 
  A
• 
  B
• 
  C
• 
  D

A die is rolled. What is the probability that the dots on the top are greater than 4?

• 1/4 A
• 1/2 B
• 1/3 C
• 1/33 D

The probability that a slip of number divisible by 4 is picked from the slips bearing numbers 1, 2, 3, ...10 is

• 1/5 A
• 1/4 B
• 1/3 C
• 1/2 D

n(n - 1) (n - 2) in factorial form is

• 
  A
• 
  B
• 
  C
• 
  D

Five engineering, four mathematics, two chemistry books are placed on a table at random.The probability that the books of each kind are all together is

• 
  A
• 
  B
• 
  C
• 
  D

The sum of all positive integral multiple of 5 less than 100 is

• 950 A
• 760 B
• 1230 C
• 875 D

A box containing 10 mangoes out of which 4 are rotter. Two mangoes are taken together from the box. If one of them is found to be good, the probability that the other is also good is

• 1 / 3 A
• 8 / 15 B
• 5 / 13 C
• 5 / 9 D

A combination lock on a suitcase has 3 wheels each labeled with nine digits from 1 to 9. If an opening combination is a particular sequence of three digits with no repeats, the probability of a person guessing the right combination is

• 1 / 500 A
• 1 / 504 B
• 1 / 252 C
• 1 / 250 D

• n! A
• 0! B
• 1 C
• None of these D

When a selection of object is made without paying regard to the order of selection, it is called

• Sequence A
• Series B
• Combination C
• Permutation D

A committee consists of 9 experts taken from three institutions A, B, and C, of which 2 are from, A, 3 form B and 4 from C. If three experts resign, then the probability that they belong to different institutions is

• 1 / 729 A
• 1 / 24 B
• 1 / 21 C
• 2 / 7 D

The sum of all odd numbers between 100 and 200 is

• 6200 A
• 7500 B
• 6500 C
• 3750 D

What is the probability of being born on Wednesday?

• 1/7 A
• 1/2 B
• 1/3 C
• 1/8 D

A key ring is an example of

• Permutation A
• Circular permutation B
• Combination C
• None D

A bag contains 7 whit, 5 black and 4 rd balls. If two balls are drawn at random from the bag, the probability that they are not of the same color is

• 73 / 120 A
• 83 / 120 B
• 67 / 120 C
• 43 / 120 D

Product of any n consecutive positive integers is divisible by

• n A
• √n B
• n! C
• None D

Three dice are thrown together. The probability of getting a total of at least 6 is

• 103 / 108 A
• 10 / 216 B
• 93 / 108 C
• None of these D

The number of 5-digit number that can be formed from the digits 1,2,4,6,8, when 2 and 8 are never together is

• 72 A
• 48 B
• 144 C
• 20 D

n different objects can be arranged taken all at a time in ______

• (n + 1)! ways A
• (n - 1)! ways B
• n! ways C
• n ways D

• 1.5 A
• 1.2 B
• 8 C
• None of these D

How many terms of the A.P 3,6,9,12,15...........must be taken to make the sum 108

• 8 A
• 6 B
• 7 C
• 36 D

An experiment yields 3 mutually exclusive and exhaustive events A, B, C, if P(A) =2 and P(B) = 3. then P(C) =

• 1 / 11 A
• 2 / 11 B
• 3 / 11 C
• 6 / 11 D

A box contains 10 red 30 white and 20 black marbles When a marble is drawn at random the probability that it is either red or white is

• 1/6 A
• 1/3 B
• 1/2 C
• 2/3 D

• 
  A
• 
  B
• 
  C
• 
  D

5 unbiased coins coins are tossed simultaneously. The probability of getting at least one head is

• 1 / 32 A
• 31 / 32 B
• 1 / 16 C
• None of these D

The number of ways of arranging the letter AAAAA BBB CCC D EE F in a row when no two C's are together is

• 
  A
• 
  B
• 
  C
• 
  D

How many different 5-digit even numbers are possible form digit 1,2,4,6,8

• 4 : 4! A
• 4! B
• 5! C
• 4!+4! D