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

6! = ______

• 360 A
• 720 B
• 6.5.4 C
• None of these D

Two unbiased dice are thrown. The probability that the total score is > 5 is

• 1 / 18 A
• 7 / 18 B
• 13 / 18 C
• 11 / 18 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

Number of selections of n different things out of n

• 1 A
• nPr B
• n! C
• nPr D

• 
  A
• 
  B
• 
  C
• 
  D

• 
  A
• 
  B
• 
  C
• 
  D

n!/(n-1)!=

• n A
• n! B
• (n-1)! C
• 0! D

In how many ways can 5 persons be seated at a round table

• 5! A
• 4! B
• 3! C
• 120 D

How many signals can be given by 5 flags of different colours, using 3 flags at a time

• 120 A
• 60 B
• 24 C
• 15 D

The probability to get an odd number in a dice thrown once is

• 6 A
• 1 B
• 1/6 C
• 1/2 D

20. 19. 18. 17= _______

• 
  A
• 
  B
• 
  C
• 
  D

A die is thrown 100 times. If getting an odd number is considered a success, the variance of the number of successes is

• 50 A
• 25 B
• 10 C
• 100 D

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

The sum if 1,3,5,7,9........ up to 20 terms is

• 400 A
• 472 B
• 563 C
• 264 D

A bag contains 5 white, 7 red and 5 black balls. If four balls are drawn one by one with replacement, the probability that none is white is

• (11/16)² A
• (5/16)² B
• (11/16)⁴ C
• (5/16)⁴ D

• 
  A
• 
  B
• 
  C
• 
  D

How many 3 digit numbers can be formed by using each one of the digit 2, 3, 5, 7, 9 only once?

• 15 A
• 24 B
• 60 C
• 120 D

A class contains nine boys and three girls, in how many ways can the teacher choose a committee of four?

• 60 A
• 460 B
• 495 C
• 272 D

• 6 A
• 360 B
• 120 C
• 24 D

• 5 A
• 10 B
• 20 C
• 30 D

Number of permutations of n distinct objects taken r(<n - 3) at a time which exclude 3(<n) particular objects is

• 3! P(n, r - 3) A
• P(n, 3) P(n, r - 3) B
• P(r, r)P(n, r - 3) C
• P(n - 3, r) D

An unbiased die is thrown. Then the probability of getting a prime is

• 1/2 A
• 2/3 B
• 3/4 C
• None of these D

How many arrangements of the letters of the word MI SSI PPI, taken all together can be made?

• 
  A
• 
  B
• 
  C
• 
  D

Number of combination of zero or more things out of n different things

• nPn A
• nPr B
• nCr C
• 2n 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

Three unbiased coins are tossed. Then the probabilities of getting two heads is

• 3/8 A
• 1/8 B
• 1/4 C
• None of these D

• 0.9 A
• 0.74 B
• 0.2016 C
• None of these D

If A and B are two disjoint events then

• P(A∪B)=P(A)+P(B) A
• P(A∪B)=P(A)-P(A∪B) B
• P(A∪B)=P(A)or P(B) C
• None D

• 0 A
• -1 B
• 1 C
• 2 D

There are n seats round a table numbered 1, 2, 3 .... n. The number of ways in which m person can take seats is

• ⁿP_m A
• ⁿC_mx (m - 1) ! B
• ^n-1P_m C
• None of these D