On any given day, Cooper either wears a blue jumper or he wears a green jumper or he…

MATHEMATICS · Multi-part · A Level · Mathematics · Statistical distributions · Statistical distributions

Problem

On any given day, Cooper either wears a blue jumper or he wears a green jumper or he does not wear a jumper. The probability that he wears a blue jumper is 0.6 and the probability that he wears a green jumper is 0.3. Whether Cooper wears a jumper of either colour, or does not wear a jumper, on any day is independent of his choice on any other day. (1) Find the probability, that in a week (7 days), Cooper wears a blue jumper on at least 5 days. (2) Use a suitable approximation to find the probability that, in any 150-day period, Cooper does not wear a jumper on fewer than 22 days.

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