

InterviewSolution
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Three coins are tossed together. Find the probability of getting:(i) exactly two heads(ii) at least two heads(iii) at least one head and one tail(iv) no tails |
Answer» When 3 coins are tossed together, Total no. of possible outcomes = 8 {HHH, HHT, HTH, HTT, THH,THT, TTH, TTT} (i) Probability of an event = (No. of favorable outcomes)/(Total no. of possible outcomes) Let E ⟶ event of getting exactly two heads No. of favourable outcomes = 3 {HHT, HTH, THH} Total no. of possible outcomes = 8 P(E) = 3/8 (ii) E ⟶ getting at least 2 Heads No. of favourable outcomes = 4 {HHH, HHT, HTH, THH} Total no. of possible outcomes = 8 P(E) = 4/8 = 1/2 (iii) E⟶ getting at least one Head & one Tail No. of favourable outcomes = 6 {HHT, HTH, HTT, THH, THT, TTH} Total no. of possible outcomes = 8 P(E) = 6/8 = 3/4 (iv) E ⟶ getting no tails No. of favourable outcomes = 1 {HHH} Total no. of possible outcomes = 8 P(E) = 1/8 |
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