Explore topic-wise MCQs in General Aptitude.

This section includes 992 Mcqs, each offering curated multiple-choice questions to sharpen your General Aptitude knowledge and support exam preparation. Choose a topic below to get started.

101.

For any two events A and B, the probability that at least one of them occur is 0.6. If A and B occur simultaneously with a probability 0.3, then P(A') + P(B') is

A. 0.9
B. 1.15
C. 1.1
D. 1
Answer» D. 1
102.

Let X1 and X2 be independent random variables each having geometric distribution qk p ; k = 0, 1, 2, …. Then the conditional distribution of X1 given X1 + X2 is

A. Binomial
B. Poisson
C. Uniform
D. Exponential
Answer» D. Exponential
103.

Five horses are in a race. Mr. A selects two of the horses at random and bets on them. The probability that Mr. A selected the winning horse is

A. 3 / 5
B. 1 / 5
C. 2 / 5
D. 4 / 5
Answer» D. 4 / 5
104.

2 dices are thrown randomly. Find the probability that the sum would be 6.

A. 11/36
B. 5/36
C. 25/36
D. 1/6
E. 1/18
Answer» C. 25/36
105.

For two events, A and B, it is given that \({\rm{P}}\left( {\rm{A}} \right) = \frac{3}{5},{\rm{\;P}}\left( {\rm{B}} \right) = \frac{3}{{10}}\) and \({\rm{P}}\left( {{\rm{A|B}}} \right) = \frac{2}{3}\). If A̅ and B̅ are the complementary events of A and B, then what is P(A̅ | B̅) equal to?

A. \(\frac{3}{7}\)
B. \(\frac{3}{4}\)
C. \(\frac{1}{3}\)
D. \(\frac{4}{7}\)
Answer» B. \(\frac{3}{4}\)
106.

A box contains 15 blue balls and 45 black balls. If 2 balls are selected randomly, without replacement, the probability of an outcome in which the first selected is a blue ball and the second selected is a black ball, is ______.

A. \(\dfrac{45}{236}\)
B. \(\dfrac{1}{4}\)
C. \(\dfrac{3}{16}\)
D. \(\dfrac{3}{4}\)
Answer» B. \(\dfrac{1}{4}\)
107.

An unbiased die with faces marked 1, 2, 3, 4, 5 and 6 is rolled four times. Out of four face values obtained, the probability that the minimum face value is not less than 2 and the maximum face value is not greater than 5 is

A. 16/81
B. 1/81
C. 80/81
D. 65/81
Answer» B. 1/81
108.

Find the probability of getting exactly 9 heads if an unbiased coin is tossed 20 times ?

A. 20C8 \(\rm \frac{1}{2}^{20}\)
B. 20C9 \(\rm \frac{1}{2}^{20}\)
C. 20C9 \(\rm \frac{1}{2}^{10}\)
D. 20C9 \(\rm \frac{1}{2}^{40}\)
Answer» C. 20C9 \(\rm \frac{1}{2}^{10}\)
109.

A dice is thrown. What is the probability of getting a number not greater than 5?

A. \(\frac{6}{5}\)
B. \(\frac{7}{5}\)
C. \(\frac{5}{6}\)
D. \(\frac{5}{7}\)
Answer» D. \(\frac{5}{7}\)
110.

A die is thrown. The probability of getting a number greater than 6 is:

A. \(\frac{1}{2}\)
B. \(\frac{1}{6}\)
C. 1
D. 0
Answer» E.
111.

A question is given to three students A, B and C whose chances of solving it are \(\frac{1}{2},\frac{1}{3}\) and \(\frac{1}{4}\) respectively. What is the probability that the question will be solved?

A. \(\frac{1}{{24}}\)
B. \(\frac{1}{4}\)
C. \(\frac{3}{4}\)
D. \(\frac{{23}}{{24}}\)
Answer» D. \(\frac{{23}}{{24}}\)
112.

A problem in Mathematics is given to 3 students A, B and C. If the probability of A solving the problem is \(\dfrac{1}{2}\) and B not solving it is \(\dfrac{1}{4}\) and the whole probability of the problem being solved is \(\dfrac{63}{64}\), then what is the probability of solving it by C?

A. \(\dfrac18\)
B. \(\dfrac1{64}\)
C. \(\dfrac78\)
D. \(\dfrac12\)
Answer» D. \(\dfrac12\)
113.

A bag has four cuboids and three cubes. What is probability of getting 1 cube ?

A. 3/7
B. 4/7
C. 1
D. 2/7
Answer» B. 4/7
114.

A card is drawn from a well-shuffled deck of 52 cards. What is the probability that it is queen of spade?

A. \(\frac{1}{{52}}\)
B. \(\frac{1}{{13}}\)
C. \(\frac{1}{4}\)
D. \(\frac{1}{8}\)
Answer» B. \(\frac{1}{{13}}\)
115.

If {x} is a continuous, real valued random variable defined over the interval (− ∞, + ∞) and its occurrence is defined by the density function given as: \({\rm{ f}}\left( {\rm{x}} \right){\rm{ = }}\frac{{\rm{1}}}{{\sqrt {{\rm{2\pi }}\;} }{{\rm{\times b}}}}\times{{\rm{e}}^{{\rm{ - }}\frac{{\rm{1}}}{{\rm{2}}}{{\left( {\frac{{{\rm{x - a }}}}{{\rm{b }}}} \right)}^{\rm{2}}}}}\)where 'a' and 'b' are the statistical attributes of the random variable {x}. The value of the integral \( \mathop \smallint \limits_{-\infty}^a\frac{{\rm{1}}}{{\sqrt {{\rm{2\pi }}\;} }{{\rm{\times b}}}}\times{{\rm{e}}^{{\rm{ - }}\frac{{\rm{1}}}{{\rm{2}}}{{\left( {\frac{{{\rm{x - a }}}}{{\rm{b }}}} \right)}^{\rm{2}}}}}dx\) is

A. 1
B. 0.5
C. π
D. 2 π
Answer» C. π
116.

In throwing of a dice, the probability of getting an even number is

A. \(\frac{1}{2}\)
B. \(\frac{1}{3}\)
C. \(\frac{1}{6}\)
D. \(\frac{1}{4}\)
Answer» B. \(\frac{1}{3}\)
117.

A coin is tossed 5 times. The probability that tail appears an odd number of times, is

A. \(\frac{1}{2}\)
B. \(\frac{1}{3}\)
C. \(\frac{2}{5}\)
D. \(\frac{1}{5}\)
Answer» B. \(\frac{1}{3}\)
118.

In how many ways all letters of word ASSERTION can be arranged?

A. 5760
B. 362880
C. 181440
D. 6480
Answer» D. 6480
119.

Person X can solve 80% of the ISRO question paper and Person Y can solve 60%. The probability that at least one of them will solve a problem from the question paper, selected at random is:

A. 0.48
B. 0.7
C. 0.88
D. 0.92
Answer» E.
120.

A box contains 4 red balls, 5 green balls and 6 white balls. A ball is drawn at random from the box. What is the probability that the ball drawn is either red or green?

A. 2/5
B. 1/5
C. 3/5
D. 7/15
Answer» D. 7/15
121.

Probabilities to solve a certain problem by Pragati and Tripti are respectively \(\frac{1}{3}\) and \(\frac{1}{2}\). The probability that the problem will be solved is:

A. \(\frac{1}{2}\)
B. \(\frac{1}{3}\)
C. \(\frac{2}{3}\)
D. \(\frac{1}{6}\)
Answer» D. \(\frac{1}{6}\)
122.

Let us consider ∪ as a combined set of 70 elements. If A, B are subsets of ∪ such that n(A) = 20, n(B) = 30 and n(A ∩ B) = 10 then n (A '∩ B') =

A. 40
B. 60
C. 30
D. None of these
Answer» D. None of these
123.

A bag contains 4 red, 5 black and 6 white balls. If a ball is drawn from the bag, then what is the probability that it is black ?

A. \(\frac{1}{3}\)
B. \(\frac{4}{15}\)
C. \(\frac{2}{5}\)
D. \(\frac{2}{15}\)
Answer» B. \(\frac{4}{15}\)
124.

If A and B are two events such that \(\rm P(A\cup B) = \dfrac{5}{6}\), \(\rm P(A\cap B) = \dfrac{1}{3}\) and \(\rm P(\bar{B}) = \dfrac{1}{2}\), then the events A and B are:

A. Dependent.
B. Independent.
C. Mutually exclusive.
D. None of these.
Answer» C. Mutually exclusive.
125.

A special dice with numbers 1, -1, 2, -2, 0 and 3 is thrown thrice. What is the probability that the sum of the numbers occurring on the upper face is zero?

A. 1/72
B. 1/8
C. 7/72
D. 25/216
Answer» E.
126.

If we throw two coins in the air, then the probability of getting both tails will be:

A. 1/2
B. 1/4
C. 2
D. 4
Answer» C. 2
127.

Match List I with List II.Let A and B be events with P(A) = \(\frac{2}{3}\), P(B) = \(\frac{1}{2}\) and P (A ∩ B) = \(\frac{1}{3}\)List- IList - IIProbability of an event Value(A) P (A ∩ Bc)(I) \(\frac{2}{3}\)(B) P (A ∪ Bc)(II) \(\frac{1}{3}\)(C) P (Ac ∩ Bc)(III) \(\frac{5}{6}\)(D) P (Ac ∪ Bc)(IV) \(\frac{1}{6}\)(Here c stands for complement)Choose the correct answer from the options given below:

A. (A)-(II), (B)-(III), (C)-(IV), (D)-(I)
B. (A)-(IV), (B)-(III), (C)-(II), (D)-(I)
C. (A)-(I), (B)-(III), (C)-(IV), (D)-(II)
D. (A)-(II), (B)-(IV), (C)-(III), (D)-(I)
Answer» B. (A)-(IV), (B)-(III), (C)-(II), (D)-(I)
128.

A medicine is known to be 75% effective to cure a patient. If the medicine is given to 5 patients, what is the probability that at least one patient is cured by this medicine?

A. \(\frac{1}{{1024}}\)
B. \(\frac{{243}}{{1024}}\)
C. \(\frac{{1023}}{{1024}}\)
D. \(\frac{{781}}{{1024}}\)
Answer» D. \(\frac{{781}}{{1024}}\)
129.

Among the four normal distributions with probability density functions as shown below, which one has the lowest variance?

A. I
B. II
C. III
D. IV
Answer» E.
130.

If 1 card is taken out of a group of cards, then the probability of that card is not ace is -

A. 12/13
B. 1/13
C. 2/13
D. 3/13
Answer» B. 1/13
131.

A coin is tossed. What is the probability of getting a head?

A. 1/2
B. 1/4
C. 1/3
D. 1/5
Answer» B. 1/4
132.

An unbiased coin is tossed. If the outcome is a head then a pair of unbiased dice is rolled and the sum of the numbers obtained on them is noted. If the toss of the coin results in tail then a card from a well-shuffled pack of nine cards numbered 1, 2, 3, …., 9 is randomly picked and the number on the card is noted. The probability that the noted number is either 7 or 8 is:

A. 13/36
B. 15/72
C. 19/72
D. 19/36
Answer» D. 19/36
133.

In a class there are 15 boys and 10 girls. Three students are selected at random. What is the probability that all are boys?

A. 91/460
B. 95/460
C. 97/460
D. 99/460
Answer» B. 95/460
134.

If a card is drawn at random from a well shuffled pack of 52 playing cards, then the probability of getting a red coloured face card is

A. \(\frac{2}{{13}}\)
B. \(\frac{1}{{13}}\)
C. \(\frac{3}{{26}}\)
D. \(\frac{3}{{52}}\)
Answer» D. \(\frac{3}{{52}}\)
135.

A chain of video stores sells three different brands of DVD players. Of its DVD player sales, 50% are brand 1, 30% are brand 2 and 20% are brand 3. Each manufacturer offers one year warranty on parts and labor. It is known that 25% of brand 1 DVD players require warranty repair work whereas the corresponding percentage for brands 2 and 3 are 20% and 10% respectively. The probability that a randomly selected purchaser has a DVD player that will need repair while under warranty, is:

A. 0.795
B. 0.205
C. 0.125
D. 0.06
Answer» C. 0.125
136.

A person wanted to visit four places Chennai, Bangalore, Delhi and Mumbai on one trip. Find the probability of the person visiting Chennai just before Mumbai.

A. 1/2
B. 1/12
C. 1/4
D. 1/6
Answer» D. 1/6
137.

Minimum number of times a fair coin must be tossed so that the probability of getting at least one head is more than 99% is:

A. 5
B. 6
C. 8
D. 7
Answer» E.
138.

A dice is thrown, what is the probability getting prime number?

A. 1/2
B. 2/3
C. 1/3
D. 4/5
Answer» B. 2/3
139.

Consider the following in respect of two events A and B:1) P(A occurs but not B) = P(A) – P(B) if B ⊂ A2) P(A alone or B alone occurs) = P(A) + P(B) – P(A ∩ B)3) P(A ∪ B) = P(A) + P(B) if A and B are mutually exclusiveWhich of the above is/are correct?

A. 1 only
B. 1 and 3 only
C. 2 and 3 only
D. 1 and 2 only
Answer» C. 2 and 3 only
140.

A coin is tossed 10 times and the outcomes are observed as : H, T, H, T, T, H, H, T, H, H (H is Head; T is Tail)What is the probability of getting Head?

A. \(\dfrac{3}{5}\)
B. \(\dfrac{4}{5}\)
C. \(\dfrac{2}{5}\)
D. \(\dfrac{1}{5}\)
Answer» B. \(\dfrac{4}{5}\)
141.

If \(P\left( B \right) = \frac{3}{4},\;P\left( {A \cap B \cap {C^c}} \right) = \frac{1}{3}\) and \(P\;\left( {{A^c}\; \cap \;B\; \cap \;{C^c}} \right) = \frac{1}{3},\) then what is P (B ∩ C) equal to?

A. \(\frac{1}{{12}}\)
B. \(\frac{3}{{4}}\)
C. \(\frac{1}{{15}}\)
D. \(\frac{1}{{9}}\)
Answer» B. \(\frac{3}{{4}}\)
142.

A person throws two fair dice. He wins Rs. 15 for throwing a doublet (same numbers on the two dice), wins Rs. 12 when the throw results in the sum of 9, and loses Rs. 6 for any other outcome on the throw. Then the expected gain/loss (in Rupees) of the person is:

A. \(\frac{1}{2}\) gain
B. \(\frac{1}{4}\) loss
C. \(\frac{1}{2}\) loss
D. 2 gain
Answer» D. 2 gain
143.

In a class of 125 students 70 passed in Maths 55 in statistics and 30 in both. probability that a student selected at random from the class has passed only in one subject is

A. 13/25
B. 3/25
C. 17/25
D. 8/25
Answer» B. 3/25
144.

An experiment succeeds twice as often as it fails. The probability that in the next six trials there will be at least four successes, is:

A. \(\rm \dfrac{240}{729}\)
B. \(\rm \dfrac{496}{729}\)
C. \(\rm \dfrac{220}{729}\)
D. \(\rm \dfrac{233}{729}\)
Answer» C. \(\rm \dfrac{220}{729}\)
145.

If two fair dice are rolled then what is the conditional probability that the first dice lands on 6 given that the sum of numbers on the dice is 8?

A. \(\frac{1}{3}\)
B. \(\frac{1}{4}\)
C. \(\frac{1}{5}\)
D. \(\frac{1}{6}\)
Answer» D. \(\frac{1}{6}\)
146.

If two dice are thrown in the air, the probability of getting sum as 3 will be

A. 2/18
B. 3/18
C. 1/18
D. 1/36
Answer» D. 1/36
147.

In throwing of two dice, what is the probability of getting an odd sum?

A. 1/3
B. 1/2
C. 1/4
D. 1/6
Answer» C. 1/4
148.

A bag has 5 white marbles, 8 red marbles and 4 purple marbles. If we take a marble randomly, then what is the probability of not getting purple marble? (approx.)

A. 0.5
B. 0.66
C. 0.08
D. 0.77
Answer» E.
149.

If a fair die is rolled 4 times, then what is the probability that there are exactly 2 sixes?

A. \(\frac{5}{{216}}\)
B. \(\frac{{25}}{{216}}\)
C. \(\frac{{125}}{{216}}\)
D. \(\frac{{175}}{{216}}\)
Answer» C. \(\frac{{125}}{{216}}\)
150.

If 'Head' appears consecutively in the first three tosses of a fair/unbiased coin, what is the probability of 'Head' appearing in the fourth toss also?

A. 1 / 8
B. 7 / 8
C. 1 / 16
D. 1 / 2
Answer» E.