ECAT Mathematics Chapter 9 Permutation, Combination and Probability

• 1 / 2 A
• 1 / 3 B
• 1 / 4 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

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

• 
  A
• 
  B
• 
  C
• 
  D

The sample space for tossing a coin twice is

• {H, T} A
• {HH, HT, TH, TT} B
• {H, T, HH} C
• {HH, HT, TT} D

Number of ways of writing the letters of WORD taken all at a time is

• 24 A
• 4 B
• 12 C
• 6 D

• 
  A
• 
  B
• 
  C
• 
  D

• 6 A
• 360 B
• 120 C
• 24 D

The probability that a person A will be alive 15 years hence is 5/7 and the probability that another person B will be alive 15 years hence is 7/9. Find the probability that both will be alive 15 years hence

• 4/63 A
• 5/9 B
• 45/49 C
• None of these D

0! = ______

• 0 A
• 1 B
• 2 C
• Not defined D

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

• nPn A
• nPr B
• nCr C
• 2n D

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

• 
  A
• 
  B
• 
  C
• 
  D

If two balls are drawn from a bag containing 3 white, 4 black and 5 red balls. Then the probability that the drawn balls are of different colours is

• 1 / 66 A
• 3 / 66 B
• 19 / 66 C
• 47 / 66 D

All letters of the word "AGAIN" are permuted in all possible ways and the words so formed (with or without meaning) are written as in dictionary, then the 50th word is

• NAAGI A
• NAAIG B
• IAANG C
• INAGA 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

A dice is rolled. The probability that the dots on the top are greater than 4 is

• 1/6 A
• 1/3 B
• 1/2 C
• 1 D

In school there are 150 students Out of these 80 students enrolled for mathematics class 50 enrolled for English class and 60 enrolled for Physics class The student enrolled for English cannot attend any other class but the students of mathematics and Physics can take two courses at a time Find the number of students who have taken both physics and mathematics.

• 40 A
• 30 B
• 50 C
• 20 D

(n + 2) (n + 1) n= ______

• 
  A
• 
  B
• 
  C
• 
  D

How many arrangements of the letters of the word ADDING can be made

• 
  A
• 
  B
• 
  C
• 
  D

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

• 6 A
• 1 B
• 1/6 C
• 1/2 D

• 
  A
• 
  B
• 
  C
• 
  D

• 8 A
• 1/56 B
• 56 C
• None of these D

• 0 A
• 20 B
• 90 C
• 80 D

Two cards are drawn at random without replacement. the probability that the first is a king and second is not a king is

• 48 / 663 A
• 24 / 663 B
• 12 / 663 C
• None of these D

• 
  A
• 
  B
• 
  C
• 
  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

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

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

• 120 A
• 5 B
• 4 C
• 6 D

• 
  A
• 
  B
• 
  C
• 
  D