Dice
What is the probability that you will roll a 4 and then a 5 with a die?
1/6 x 1/6 = 1/36
There are 2 bars of dark , 3 bars of white, 5 bars of hazelnut and 4 bars of milk chocolate in a bag. If you choose 1, what is the probability that it will be white?
3 / 14 = 0.21
Katie got a deck of cards and she is drawing cards. What is the probability that she'll draw a heart if she draws one card? (Regular deck with 52 cards.)
8 / 52 = 2 / 13
A class of 30 are doing Secret Santa. What is the probability that Katie will get Josh?
1 / 29 = 0.034
What is the probability that the sum of the numbers on two die is 4?
3/36 = 1/12
There are 2 bars of dark , 3 bars of white, 5 bars of hazelnut and 4 bars of milk chocolate in a bag. If you choose two, what is the probability that both of them are hazelnut?
(5 choose 2) / (14 choose 2) = 10 / 91 = 0.11
Katie got a deck of cards and she is drawing cards. What is the probability that the first is a heart and the second is a spade?
(8 / 52) x (8 / 51) = 16 / 663
In a class of 30, there are 14 boys and 16 girls. 5 of them are needed for a Christmas performance. What is the probability that all 5 them will be girls if we choose randomly?
(16 choose 5) / (30 choose 5) = 8 / 261 = 0.03
What is the probability that if you roll a regular die 3 times, all the rolled numbers are more than 4?
2/6 x 2/6 x 2/6= 8 / 216 = 1 / 27
There are 2 bars of dark , 3 bars of white, 5 bars of hazelnut and 4 bars of milk chocolate in a bag. If you choose 4, what is the probability that there is 1 of each type?
(2 x 3 x 5 x 4) / (14 choose 4) = 120 / 1001 = 0.12
Katie got a deck of cards and she is drawing cards. She draws two cards without replacement. What is the probability that both of them are king?
(4 / 52) x (3 / 51) = 1 / 221
In a class of 30, there are 14 boys and 16 girls. 5 of them are needed for a Christmas performance. What is the probability that there will be exactly 3 boys and 2 girls if we choose randomly?
((14 choose 3) x (16 choose 2)) / (30 choose 5) = 80 / 261 = 0.3
What is the probability that if you roll a regular die 5 times, there will be exactly 2 sixes?
(5 choose 2) x (1/6)2 x (5/6)3 = 625 / 3888 = 0.16
There are 2 bars of dark, 3 bars of white, 5 bars of hazelnut and 4 bars of milk chocolate in a bag. If you choose 5 what is the probability that there are exactly 3 hazelnut and 2 milk?
((5 choose 3) x (4 choose 2)) / (14 choose 5) = 30 / 1001 = 0.03
Katie got a deck of cards and she is drawing cards. She draws two cards with replacement. What is the probability that both of them are king?
(4/52)2 = 1 / 169
The school gives 10 presents to each class. A student can get more than one present. What is the probability that Katie will get nothing? (There are 30 students in her class)
(29/30)10 = 0.71
What is the probability that if you roll a regular die 5 times, there will be at most 1 six?
(5 choose 1) x (1/6)1 x (5/6)4 + (5/6)5 = 3125 / 3888 = 0.8
There are 2 bars of dark , 3 bars of white, 5 bars of hazelnut and 4 bars of milk chocolate in a bag. You choose 5 with replacement. What is the probability that exactly 2 of them are white?
(5 choose 2) x (3/14)2x(11/14)3 = 0.22
Katie got a deck of cards and she is drawing cards. She draws 6 cards with replacement. What is the probability that exactly half of them are diamonds?
(6 choose 3) x (8/52)3 x (44/52)3 = 0.04
The school gives 10 presents to each class. A student can get more than one present. What is the probability that Katie will get exactly 2 presents? (There are 30 students in her class)
(10 choose 2) x (1 / 30)2 x (29/30)8 = 0.038