Few questions (Starting from Q. No. 12) from the Class 10 Maths NCERT Exemplar Exercise 13.1 are given below:

Question. 12   If an event cannot occur, then its probability is

(a) 1                        (b) 3/4                        (c) 1/2                (d) 0

Answer. (d)   

Explanation:

The event which cannot occur is called the impossible event with a probability equal to zero.

Question. 13   Which of the following cannot be the probability of an event?

(a) 1/3                     (b) 0.1                  (c) 3                       (d) 17/16

Answer. (d)                   

Explanation:

Probability of an event always lies between 0 and 1.

Question. 14   An event is very unlikely to happen. Its probability is closest to

(a) 0.0001               (b) 0.001               (c) 0.01                    (d) 0.1

Answer. (a)

Explanation:

The probability of an event which is very unlikely to happen is closest to zero and from the given options 0.0001 is closest to zero.

Question. 15   If the probability of an event is P, then the probability of its complementary event will be

(a) P – 1                      (b) P                  (c) 1 – P                  (d) 1 – 1/P

Answer. (c)   

Explanation:

Since, probability of an event + probability of its complementary event = 1.

∴ Probability of its complementary event = 1 – Probability of an event = 1 – P

Question. 16   The probability expressed as a percentage of a particular occurrence can never be

(a) less than 100                                        (b) less than 0

(c) greater than 1                                       (d) anything but a whole number

Answer. (b)

Explanation:

The probability expressed as a percentage always lies between 0 to 100. So, it cannot be less than 0.

Question. 17   lf P(A) denotes the probability of an event A, then

(a) P(A) 1        (c) 0 ≤ P(A) ≤ 1           (d) –1 ≤ P(A) ≤ 1

Answer. (c)   

Explanation:

The probability of an event always lies between 0 and 1.

Question. 18   If a card is selected from a deck of 52 cards, then the probability of its being a red face card is

(a) 3/26                    (b) 3/13                 (c) 2/13                    (d) 1/2

Answer. (a)   

Explanation:

In a deck of 52 cards, there are 12 face cards with 6 red and 6 black cards.

So, probability of getting a red face card = 6/52 = 3/26

Question. 19   The probability that a non-leap year selected at random will contain 53 Sundays is

(a) 1/7                           (b) 2/7                    (c) 3/7                    (d) 5/7

Answer. (a)

Explanation:

A non-leap year has 365 days with 52 weeks and 1 odd day. This 1 odd day may be any day of the week.

Thus, out of 7 days, there is 1 favourable event that this 1 day is Sunday.

Hence the probability of getting 53 Sundays = 1/7