Class 10 - Chapter 14: Probability

Section A (1 Mark each)

Q1. A lot consists of 144 ball pens of which 20 are defective and the others are good. Nuri will buy a pen if it is good, but will not buy if it is defective. The shopkeeper draws one pen at random and gives it to her. What is the probability that she will buy it?

(a) $\frac{5}{36}$ (b) $\frac{20}{144}$ (c) $\frac{31}{36}$ (d) $\frac{124}{140}$

Q2. A child has a die whose six faces show the letters as given below:
A, B, C, D, E, A
The die is thrown once. What is the probability of getting 'A'?

(a) $\frac{1}{6}$ (b) $\frac{1}{3}$ (c) $\frac{1}{2}$ (d) $\frac{1}{4}$

Q3. If the probability of winning a game is $0.3$, what is the probability of losing it?

(a) $0.6$ (b) $0.7$ (c) $0.3$ (d) $1.0$

Q4. Assertion (A): The probability of getting a number greater than 6 in a single throw of a die is 0.
Reason (R): An event which is impossible to occur has probability 0.

(a) Both A and R are true and R is the correct explanation of A. (b) Both A and R are true but R is not the correct explanation of A. (c) A is true but R is false. (d) A is false but R is true.

Section B (2 Marks each)

Q5. Find the probability that a leap year selected at random will contain 53 Sundays.

Solve on white paper.

Q6. A box contains 5 red marbles, 8 white marbles and 4 green marbles. One marble is taken out of the box at random. What is the probability that the marble taken out will be (i) red? (ii) not green?

Solve on white paper.

Q7. A letter is chosen at random from the letters of the word 'ASSOCIATION'. Find the probability that the chosen letter is a vowel.

Solve on white paper.

Section C (3 Marks each)

Q8. A jar contains 24 marbles, some are green and others are blue. If a marble is drawn at random from the jar, the probability that it is green is $\frac{2}{3}$. Find the number of blue marbles in the jar.

Solve on white paper.

Q9. A game consists of tossing a one rupee coin 3 times and noting its outcome each time. Hanif wins if all the tosses give the same result i.e., three heads or three tails, and loses otherwise. Calculate the probability that Hanif will lose the game.

Solve on white paper.

Section D (5 Marks)

Q10. A bag contains 12 balls out of which $x$ are black.
(i) If one ball is drawn at random, what is the probability that it will be a black ball?
(ii) If 6 more black balls are put in the bag, the probability of drawing a black ball is now double of what it was before. Find $x$.

Solve on white paper.

Section E (4 Marks)

Q11. Case Study: Piggy Bank

A piggy bank contains hundred 50p coins, fifty ₹1 coins, twenty ₹2 coins and ten ₹5 coins. It is equally likely that one of the coins will fall out when the bank is turned upside down.

(i) What is the total number of coins in the piggy bank?

(ii) What is the probability that the coin will be a 50p coin?

(iii) What is the probability that the coin will not be a ₹5 coin?

Solve on white paper.