SolveItClass 10 · NCERT

NCERT Solutions · Class 10 Mathematics Probability

25 questions · 25 still being checked

EXERCISE 14.1 1–10 (part 1 of 3)

  1. Exercise 1

    Complete the following statements:
    (i)
    Probability of an event E + Probability of the event 'not E' = ____\displaystyle \_\_\_\_.
    (ii)
    The probability of an event that cannot happen is ____\displaystyle \_\_\_\_. Such an event is called ____\displaystyle \_\_\_\_.
    (iii)
    The probability of an event that is certain to happen is ____\displaystyle \_\_\_\_. Such an event is called ____\displaystyle \_\_\_\_.
    (iv)
    The sum of the probabilities of all the elementary events of an experiment is ____\displaystyle \_\_\_\_.
    (v)
    The probability of an event is greater than or equal to ____\displaystyle \_\_\_\_ and less than or equal to ____\displaystyle \_\_\_\_.
    NCERT’s answer
    Students find their own answers.

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  2. Exercise 2

    Which of the following experiments have equally likely outcomes? Explain.
    (i)
    A driver attempts to start a car. The car starts or does not start.
    (ii)
    A player attempts to shoot a basketball. She/he shoots or misses the shot.
    (iii)
    A trial is made to answer a true-false question. The answer is right or wrong.
    (iv)
    A baby is born. It is a boy or a girl.
    NCERT’s answer
    Take $\displaystyle 1 \mathrm{~cm}^{2}$ area and count the number of dots in it. Total number of trees will be the product of this number and the area (in $\displaystyle \mathrm{cm}^{2}$ ).

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  3. Exercise 3

    Why is tossing a coin considered to be a fair way of deciding which team should get the ball at the beginning of a football game?
    NCERT’s answer
    Rate of interest in instalment scheme is $\displaystyle 17.74$ %, which is less than $\displaystyle 18$ %. \section*{EXERCISE A2.3}

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  4. Exercise 4

    Which of the following cannot be the probability of an event? (A) 23\displaystyle \frac{2}{3} (B) -1.5\displaystyle 1.5 (C) 15\displaystyle 15% (D) 0.7\displaystyle 0.7
    NCERT’s answer
    $\displaystyle y=7$ \end{itemize}

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  5. Exercise 5

    If P(E)=0.05\displaystyle \mathrm{P}(\mathrm{E})=0.05, what is the probability of 'not E'?
    NCERT’s answer
    $\displaystyle \angle \mathrm{A}=100^{\circ}, \angle \mathrm{C}=100^{\circ}, \angle \mathrm{D}=180^{\circ}$

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  6. Exercise 6

    A bag contains lemon flavoured candies only. Malini takes out one candy without looking into the bag. What is the probability that she takes out
    (i)
    an orange flavoured candy?
    (ii)
    a lemon flavoured candy?
    NCERT’s answer
    See Theorem $\displaystyle 5.1$ of Class IX Mathematics Textbook. \section*{EXERCISE A2.2}

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  7. Exercise 7

    It is given that in a group of 3\displaystyle 3 students, the probability of 2\displaystyle 2 students not having the same birthday is 0.992. What is the probability that the 2\displaystyle 2 students have the same birthday?
    NCERT’s answer
    Yes, because of the premise. No, because $\displaystyle \sqrt{3721}=61$ which is not irrational. Since the premise was wrong, the conclusion is false. \section*{EXERCISE A1.3}

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  8. Exercise 8

    A bag contains 3\displaystyle 3 red balls and 5\displaystyle 5 black balls. A ball is drawn at random from the bag. What is the probability that the ball drawn is
    (i)
    red ?
    (ii)
    not red?
    NCERT’s answer
    (i)
    $\displaystyle \frac{3}{8}$ (ii) $\displaystyle \frac{5}{8}$

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  9. Exercise 9

    A box contains 5\displaystyle 5 red marbles, 8\displaystyle 8 white marbles and 4\displaystyle 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)
    white?
    (iii)
    not green?
    NCERT’s answer
    (i)
    $\displaystyle \frac{5}{17}$ (ii) $\displaystyle \frac{8}{17}$ (iii) $\displaystyle \frac{13}{17}$

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  10. Exercise 10

    A piggy bank contains hundred 50p coins, fifty ₹ 1\displaystyle 1 coins, twenty ₹ 2\displaystyle 2 coins and ten ₹ 5\displaystyle 5 coins. If it is equally likely that one of the coins will fall out when the bank is turned upside down, what is the probability that the coin
    (i)
    will be a 50\displaystyle 50 p coin ?
    (ii)
    will not be a ₹ 5\displaystyle 5 coin?
    NCERT’s answer
    (i)
    $\displaystyle \frac{5}{9}$ (ii) $\displaystyle \frac{17}{18}$

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