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Find the probability that the month of June may have 5 Mondays in a year.(A) \( \frac{2}{7} \)(B) \( \frac{1}{6} \)(C) \( \frac{5}{6} \)(D) \( \frac{1}{7} \) |
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Answer» → Total number of days in June = 30 → Therefore, there must be 4 Mondays, 4 Tuesdays, 4 Wednesdays, ..... 4 Sundays. → Rest days = 30 - 7 x 4 = 30 - 28 = 2. → These 2 days may be (i) Sunday & Monday, (ii) Monday & Tuesday, (iii) Tuesday & Wednesday, (iv) Wednesday & Thursday, (v) Thursday & Friday, (vi) Friday & Saturday, (vii) Saturday & Sunday. → Hence, total outcomes for these 2 days. (Rest 2 days) is n(S) = 7 → Outcomes favourable to 5 Mondays are Monday & Tuesday and Sunday & Monday. → Number of outcomes favourable to get 5 Mondays is n(E) = 2. → ∴ Probability of getting 5 Mondays in month of June is P(E) = n(E)/n(S) = 2/7. |
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