Probability

Last Updated :
Discuss
Comments

Question 1

Suppose a fair six-sided die is rolled once. If the value on the die is 1, 2, or 3, the die is rolled a second time. What is the probability that the sum total of values that turn up is at least 6?

  • 10/21

  • 5/12

  • 2/3

  • 1/6

Discuss it

Question 2

Consider a random variable X that takes values +1 and −1 with probability 0.5 each. The values of the cumulative distribution function F(x) at x = −1 and +1 are

  • 0 and 0.5

  • 0 and 1

  • 0.5 and 1

  • 0.25 and 0.75

Discuss it

Question 3

Consider a link with packet loss probability of 0.2. What is the expected number of transmissions it would take to transfer 200 packets given that the stop and wait protocol is used?
  • 125
  • 250
  • 225
  • 150
Discuss it

Question 4

When a coin is tossed, the probability of getting a Head is p,0<p<1. Let N be the random variable denoting the number of tosses till the first Head appears, including the toss where the Head appears. Assuming that successive tosses are independent, the expected value of N is

  • 1/p

  • 1/(1−p)

  • 1/p2

  • 1/(1−p2)

Discuss it

Question 5

Suppose there are 11 items in sorted order in an array. How many searches are required on the average, if binary search is employed and all searches are successful in finding the item?

  • 3.00

  • 3.46

  • 2.81

  • 3.33

Discuss it

Question 6

Out of all the 2-digit integers between 1 and 100, a 2-digit number has to be selected at random. What is the probability that the selected number is not divisible by 7?

  • 13/90

  • 12/90

  • 78/90

  • 77/90

Discuss it

Question 7

Consider a finite sequence of random values X = { x1, x2,..., xn}. Let μx be the mean and σx be the standard deviation of X. Let another finite sequence Y of equal length be derived from this as yi = a*xi + b, where a and b are positive constants. Let μy be the mean and σy be the standard deviation of this sequence. Which one of the following statements is INCORRECT?

  • Index position of mode of X in X is the same as the index position of mode of Y in Y.

  • Index position of median of X in X is the same as the index position of median of Y in Y.

  • μy = aμx+b

  • σy = aσx+b

Discuss it

Question 8

If the difference between expectation of the square of a random variable (E[X²]) and the square of the expectation of the random variable (E[X])² is denoted by R, then?

  • R = 0

  • R < 0

  • R >= 0

  • R > 0

Discuss it

Question 9

If two fair coins are flipped and at least one of the outcomes is known to be a head, what is the probability that both outcomes are heads?

  • 1/3

  • 1/4

  • 1/2

  • 2/3

Discuss it

Question 10

What is the probability that divisor of 1099 is a multiple of 1096?

  • 1/625

  • 4/625

  • 12/625

  • 16/625

Discuss it

There are 94 questions to complete.

Take a part in the ongoing discussion