Dice
What is the probability of the result of rolling a die to be an even number?
3/6 = 1/2 = 50% = 0/5
If you throw a coin in the air, what is the probability of getting heads?
1/2
A deck has 52 cards. 13 are black clubs, 13 are black spades, 13 are red hearts, and 13 are red diamonds. What is the probability of picking a black card at random?
26/52 = 2/4 = 1/2 = 50% = 0.5
In a box there are 10 red balls and 10 blue balls. You pick a random ball. What is the probability of its color to be red?
10/20 = 1/2 = 50% = 0.5
What is the probability of the result of rolling a die to be an odd number?
3/6 = 1/2 = 50% = 0.5
If you throw a coin in the air, what is the probability of getting tails?
1/2
A deck has 52 cards. 13 are black clubs, 13 are black spades, 13 are red hearts, and 13 are red diamonds. What is the probability of picking a spades card at random?
13/52 = 1/4 = 25% = 0.25
A box has 10 balls labeled A, B, C, D, ..., J. You pick up a random ball. What is the probability of this ball to be a vowel?
3/10 = 30% = 0.3
What is the probability of the result of rolling a die to be a 1?
1/6
If you throw a coin in the air twice, what is the probability of getting a head and a tail, in this order?
(1/2) x (1/2) = 1/4
A deck has 52 cards. 13 are black clubs, 13 are black spades, 13 are red hearts, and 13 are red diamonds. What is the probability of picking a black heart at random?
0/52 = 0%
A box has 10 balls labeled A, B, C, D, ..., J. You pick up a random ball. What is the probability of this ball to be a consonant?
7/10 = 70% = 0.7
What is the probability of the result of rolling a die to be a 6?
1/6
If you throw a coin in the air twice, what is the probability of getting a heads or a tail?
(1/2) + (1/2) = 1
A deck has 52 cards. 13 are black clubs, 13 are black spades, 13 are red hearts, and 13 are red diamonds. What is the probability of picking a red card or a clubs card at random?
Red = 26/52 = 1/2
Clubs = 13/52 = 1/4
(1/2) + (1/4) = (2/4) + (1/4) = (2 + 1)/4 = 3/4 = 75% = 0.75
A box has 5 blue balls, 7 red balls, and 18 green balls. What is the probability of picking a ball that is not green?
(5+7)/30 = 12/30
What is the probability of the result of rolling a die to be larger than 4?
1/3
If you throw 3 coins in the air, what is the probability of all of them showing heads?
(1/2) x (1/2) x (1/2) = 1/8
A deck has 52 cards. 13 are black clubs, 13 are black spades, 13 are red hearts, and 13 are red diamonds. What is the probability of picking 2 cards in sequence, one black and one red?
Black = 26/52
Red = 26/51
Red and black = (26/52) x (26/51) = 1/4
A rabbit has 12 houses, numbered 1, 2, 3, ..., 12. Each day he goes to a different random house. What is the probability of the rabbit choosing a house whose number is a multiple of 3?
4/12 = 1/3 = 33.33...% = 0.3333...