4. A hardware store is open on six days each week. On average the store sells 8 of a particular make of electric drill each week.
Find the probability that the store sells
- no more than 4 of the drills in a week,
- more than 2 of the drills in one day.
The store receives one delivery of drills at the same time each week.
- Find the number of drills that need to be in stock after a delivery for there to be at most a 5\% chance of the store not having sufficient drills to meet demand before the next delivery.
(3 marks)
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