ICSE-VIII-Mathematics

23: Probability Class 8 Maths

with Solutions -
  • #3
    A coin is tossed twice. Find the probability of getting: (i) exactly one head (ii) exactly one tail
    (iii) two tails (iv) two heads
    Ans : (i) Exactly one head
    Possible number of favourable outcomes = 2
    (i.e. TH and HT)
    Total number of possible outcomes = 4
    ∴ P(E) = (Number of favourable outcomes)/(Total number of possible outcomes)
    = 2/4
    = ½
    (ii) Exactly one tail
    Possible number of favourable outcomes = 2
    (i.e. TH and HT)
    Total number of possible outcomes = 4
    P(E) = (Number of favourable outcomes)/(Total number of possible outcomes)
    = 2/4
    = ½
    (iii) Two tails
    Possible number of favourable outcomes = 1
    (i.e., TT)
    Total number of possible outcome s = 4
    ∴ P(E) = (Number of favourable outcomes)/(Total number of possible outcomes)
    = ¼
    (iv) Two heads
    Possible number of favourable outcomes = 1
    (i.e. HH)
    Total number of possible outcomes = 4
    ∴ P(E) = ¼
  • #3-i
    exactly one head (ii) exactly one tail
    (iii) two tails (iv) two heads
    Ans : Exactly one head
    Possible number of favourable outcomes = 2
    (i.e. TH and HT)
    Total number of possible outcomes = 4
    ∴ P(E) = (Number of favourable outcomes)/(Total number of possible outcomes)
    = 2/4
    = ½
    (ii) Exactly one tail
    Possible number of favourable outcomes = 2
    (i.e. TH and HT)
    Total number of possible outcomes = 4
    P(E) = (Number of favourable outcomes)/(Total number of possible outcomes)
    = 2/4
    = ½
    (iii) Two tails
    Possible number of favourable outcomes = 1
    (i.e., TT)
    Total number of possible outcome s = 4
    ∴ P(E) = (Number of favourable outcomes)/(Total number of possible outcomes)
    = ¼
    (iv) Two heads
    Possible number of favourable outcomes = 1
    (i.e. HH)
    Total number of possible outcomes = 4
    ∴ P(E) = ¼