InterviewSolution
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Two dice are thrown simultaneously. What is the probability that:(i) 5 will not come up on either of them?(ii) 5 will come up on at least one?(iii) 5 will come up at both dice? |
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Answer» Total no. of possible outcomes when 2 dice are thrown = 6×6 = 36 which are { (1, 1) (1, 2) (1, 3) (1, 4) (1, 5) (1, 6) (2, 1) (2, 2) (2, 3) (2, 4) (2, 5) (2, 6) (3, 1) (3, 2) (3, 3) (3, 4) (3, 5) (3, 6) (4, 1) (4, 2) (4, 3) (4, 4) (4, 5) (4, 6) (5, 1) (5, 2) (5, 3) (5, 4) (5, 5) (5, 6) (6, 1) (6, 2) (6, 3) (6, 4) (6, 5) (6, 6) } (i) E ⟶ event of 5 not coming up on either of them No. of favourable outcomes = 25 which are { (1, 1) (1, 2) (1, 3) (1, 4) (1, 5) (1, 6) (2, 1) (2, 2) (2, 3) (2, 4) (2, 5) (2, 6) (3, 1) (3, 2) (3, 3) (3, 4) (3, 5) (3, 6) (4, 1) (4, 2) (4, 3) (4, 4) (4, 5) (4, 6) (5, 1) (5, 2) (5, 3) (5, 4) (5, 5) (5, 6) (6, 1) (6, 2) (6, 3) (6, 4) (6, 5) (6, 6) } Probability, P(E) = (No.of favorable outcomes)/(Total no.of possible outcomes) P(E) = 25/36 (ii) E ⟶ event of 5 coming up at least once {(1, 5) (2, 5) (3, 5) (4, 5) (5, 5) (5, 1) (5, 2) (5, 3) (5, 4) (5, 6) (6, 5)} P(E) = 11/36 (iii) E ⟶ event of getting 5 on both dice No. of favourable outcomes = 1 { (5, 5) } P(E) = 1/36 |
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