Easy Level Worksheet
Very Short Answer Questions (1 Mark Each)
(1) What is the probability of getting a head when a coin is tossed once? P(Head) =
Perfect! A coin has 2 equally likely outcomes: head and tail.
(2) Write the probability of drawing an ace from a well-shuffled deck of 52 cards. P(Ace) =
Excellent! There are 4 aces in a standard deck of 52 cards.
(3) What is the range of the probability of any event? Probability ranges from
Perfect! Probability can never be negative or greater than 1.
(4) A die is thrown once. What is the probability of getting an even number? P(Even) =
Correct! Half the numbers on a die are even.
(5) What is the probability of an impossible event? P(Impossible event) =
Perfect! Something that cannot happen has probability 0.
(6) Write the formula to calculate probability of an event E. P(E) =
Excellent! This is the fundamental probability formula.
(7) What is the probability of getting a red ball from a bag containing 3 red and 5 blue balls? P(Red) =
Perfect! Used the basic probability formula correctly.
Short Answer Questions (2 Marks Each)
Note: Answer each question with steps and explanation, in 2-3 sentences. Write down the answers on sheet and submit to the school subject teacher.
(1) A card is drawn from a pack of 52 cards. Find the probability of drawing: (a) a king (b) a red card P(King) =
Excellent! Applied the probability formula systematically.
(2) A bag contains 5 white balls and 3 black balls. A ball is drawn at random. What is the probability that the ball drawn is: (a) white (b) black
(a) P(White) =
(b) P(Black) =
Perfect! Notice that P(White) + P(Black) =
(3) What is the probability of getting a prime number when a die is thrown once?
P(Prime number) =
Excellent! Correctly identified all prime numbers on a die.
(4) One card is drawn from a pack of 52 cards. Find the probability of drawing a: (a) Queen of red colour (b) A face card
(a) P(Red queen) =
(b) P(Face card) =
Perfect! Systematically counted all favorable outcomes.
(5) A box contains 10 bulbs, out of which 3 are defective. One bulb is taken out at random. Find the probability that it is not defective.
P(Not defective) =
Excellent! Used complement approach effectively.
Long Answer Questions (4 Marks Each)
Note: Answer each question with steps and explanation. Write down the answers on sheet and submit to the school subject teacher.
(1) A bag contains 6 red balls and 4 green balls. A ball is drawn at random. (a) What is the probability that it is green? (b) If one more red ball is added to the bag and another ball is drawn, what is the probability that it is red now?
Part (a) P(Green) =
Part (b) P(Red) =
Excellent! Correctly handled the change in composition.
(2) A family has two children. What is the probability that both are boys if it is known that at least one is a boy?
P(Both boys|At least one boy) =
Excellent! This is conditional probability with reduced sample space.
Part B: Objective Questions (1 Mark Each)
Choose the correct answer and write the option (a/b/c/d)
(1) Probability of an event E + Probability of event not E =
(a) 0 (b) 1 (c) 2 (d) None
Correct! P(E) + P(not E) = 1. This is the complement rule.
(2) When a die is thrown once, the probability of getting 7 is:
(a) 0 (b)
Correct! A standard die only has numbers 1-6, so getting 7 is impossible.
(3) The probability of getting a head in a single coin toss is:
(a) 0 (b) 1 (c)
Correct! A fair coin has two equally likely outcomes: head and tail.
(4) A card is drawn at random from a deck. The probability of drawing a black card is:
(a)
Correct! Half the cards (26 out of 52) are black (clubs and spades).
(5) The probability of an event that is certain to happen is:
(a) 0 (b) 1 (c)
Correct! A certain event always happens, so its probability is 1.
(6) What is the probability of drawing a jack from a standard pack of 52 cards?
(a)
Correct! There are 4 jacks in 52 cards:
(7) If a die is rolled once, what is the probability of getting a number less than 4?
(a)
Correct! Numbers less than 4 are: 1, 2, 3. That's 3 out of 6, which equals
(8) A number is selected at random from 1 to 10. What is the probability it is a multiple of 5?
(a)
Correct! Multiples of 5 from 1-10 are: 5, 10. That's 2 out of 10 =
(9) What is the total number of possible outcomes when a coin is tossed twice?
(a) 1 (b) 2 (c) 3 (d) 4
Correct! Outcomes are: HH, HT, TH, TT (4 total outcomes).
(10) A bag has 5 red and 3 green marbles. What is the probability of drawing a red marble?
(a)
Correct! P(Red) = 5 red marbles / 8 total marbles =
Basic Probability Challenge
Determine whether these statements about basic probability are True or False: