P 008333 008333 x 100 833 ii What is the probability that the number

P 008333 008333 x 100 833 ii what is the probability

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P (sum> 10) = 3/36 = 0.08333 = 0.08333 x 100 = 8.33% ii) What is the probability that the number on the red die is one larger than the number on the blue die? P ( number on red die is one larger than the blue die) = 5/36 = 0.138 = 0.138 x 100 = 13.8 % iii) What is the probability that the sum of the two numbers is less than 11? P ( sum< 11) = 33/36 = 0.916 = 0.916 x 100 = 91.6% 4
5 ) Use a tree diagram to explain why the probability that a family with four children all have the same gender is 1/8 . Assume that the probability of having a girl is equal to the probability of having a boy. The first line represent child #1. The second line tells us that there are 4 ways to have 2 children 2 x 2 = 4. Line 3 gives us 8 different ways to have 3 kids 2 x 4 = 8. The fourth line gives us 16 different ways to have 4 children 2 x 8 = 16. 6) In a library box, there are 8 novels, 8 biographies and 8 war history books. If Jack selects two books at random, what is the probability that the two books are of different types? 24C2 = 276 ways of selecting 2 books from 24 books. 3 ways of choosing books of different kind Novel + biography Novel + war history Biography + history war Each pair is 8 x 8 = 64 Therefore total is 3 x 64 = 192 P ( two books are of different types) = 192/276 = 16/23 7) The probability that Prasha will score above a 90 on a mathematics test is 4/5 . What is the probability that she will score above a 90 on exactly 3 of the 4 tests this quarter? P( Prasha scores above 90 on 3 of the 4 tests) = nCr(p)^r(q)^n-r n= 4 r=3 p= q= = 4C3( )^3( )^4-3 5
= 4(0.512)( ) = 226/620 = 113/310 Therefore, the probability that she will score above 90 on exactly 3 of the 4 tests is 113/310 8) A company manufacturing laptops believes that 5% of their computers are faulty. They take a sample of 30 computers. Showing your calculations, find the probability that a) Two of the laptops are faulty.

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• Spring '19
• Probability theory, Hypergeometric Distribution, Maya Dras