Boolean algebra - math word problems

Records
Records indicate 90% error-free. If 8 records are randomly selected, what is the probability that at least 2 records have no errors?
Holidays
Of the 35 students of class were 7 on holiday in Germany and just as much in Italy. 5 students visited Austria. In none of these countries was 21 students, all three visited by one student . In Italy and Austria were 2 students and in Austria and Germany.
Probability - tickets
What is the probability when you have 25 tickets in 5000 that you not wins the first (one) prize?
The Hotel
The Holiday Hotel has the same number of rooms on each floor. Rooms are numbered with natural numbers sequentially from the first floor, no number is omitted, and each room has a different number. Three tourists arrived at the hotel. The first one was in r
PIN code
PIN on Michael credit card is a four-digit number. Michael told this to his friend: • It is a prime number - that is, a number greater than 1, which is only divisible by number one and by itself. • The first digit is larger than the second. • The second.
Dining questionnaire
In the class of 32 pupils, the class teacher delivered a satisfaction questionnaire to the school canteen. Eleven people have questioned whether they are satisfied with the dining room. The completed questionnaire also included the vote of the class teache
Three shooters
Three shooters shoot, each one time, on the same target. The first hit the target with a probability of 0.7; second with a probability of 0.8 and a third with a probability of 0.9. What is the probability to hit the target: a) just once b) at least once c
Intersect and conjuction
Let U={1,2,3,4,5,6} A={1,3,5} B={2,4,6} C={3,6} Find the following. 1. )AUB 2. )A'UB'

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