ECAT Pre Engineering MCQ Test With Answer for Chapter 9 Mathematics

Three integers are chosen at random from the first 20 integers. Then probability that their product is even, is

• 2 / 19 A
• 3 / 29 B
• 17 / 19 C
• 4 / 19 D

Which one is not defined∀n∈Z+

• -n! A
• n! B
• (-n)! C
• n!+0!=n!+1 D

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

• 
  A
• 
  B
• 
  C
• 
  D

n!/(n-1)!=

• n A
• n! B
• (n-1)! C
• 0! D

How many comittees of 5 numbers can be chosen from a group of 8 players person when each committee must include 2 particular persons

• 8! A
• 5!3! B
• 5! C
• 20 D

• 
  A
• 
  B
• 
  C
• 
  D

How many 6-Digit number can be formed without repairing any digit from the digits 0,1,2,3,4,5

• 720 A
• 600 B
• 120 C
• 6-5! D

nCn-r is equal to

• n! A
• n-1Cr B
• nCr C
• None of these 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

The value of n, when ⁿP₂= 20 is

• 3 A
• 4 B
• 6 C
• 5 D

A and B throw a dice. The probability that A's throw is not greater then B's is

• 5 / 12 A
• 7 / 12 B
• 1 / 6 C
• 1 / 2 D

Three numbers are chosen random without replacement from {1, 2, 3, ...., 10}. the probability that minimum of the chosen numbering is 3 or their maximum is 7

• 7 / 40 A
• 5 / 40 B
• 11 / 40 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

For two events A and B if P(A) = P (A/B) = 1/4 and P(B/A) = 1/2, then

• A is sub-event of B A
• A and B are mutually exclusive B
• A and B are independent and P(A/B) = 3/4 C
• None of these 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

• 0 A
• -1 B
• 1 C
• 2 D

• 110 A
• 220 B
• 1320 C
• None of these D

• 5 / 12 A
• 3 / 8 B
• 5 / 8 C
• 7 / 4 D

Probability of an impossible event is

• 0 A
• -1 B
• 1 C
• ∞ D

Two coins are tossed twice each. The probability that the head appears on the first toss and the same forces appear in the two tosses is

• 1/4 A
• 1/2 B
• 1/3 C
• 1/7 D

• 
  A
• 
  B
• 
  C
• 
  D

• 120 A
• 5 B
• 4 C
• 6 D

• 0 A
• 20 B
• 90 C
• 80 D

A machine operates if all of its three components function. The probability that the first component fails during the year is 0.14, the second component fails is 0.10 and the third component fails is 0.05. the probability that the machine will fail during the year is

• 0.2647 A
• 0.2692 B
• 0.3647 C
• None of these D

If A is an event then which of the following is true

• P(A)<0 A
• 0≥P(A)≤1 B
• P(A)>0 C
• None D

A bag contains 3 white, 4 black and 2 red balls. If 2 balls are drawn at random, then the probability that both the ball are white is

• 1/18 A
• 1/12 B
• 1/36 C
• None of these 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

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

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