Cards
What is the probability of drawing the queen of hearts out of a deck of cards?
There are 4 red and 5 black marbles in a bucket. What is the probability of drawing red?
4/9
Which event's probability is greater:
A: rolling a prime number with a regular die?
B: rolling one of the divisors of 6 with a regular die?Why?
B (4 / 6), because A is only 3 / 6
There are 10 English and 12 German students in a class of 20 students. What is the probability of choosing one who learns both languages?
2 / 20 = 0.1
This is the closest planet to the sun
Mercury
What is the probability of drawing only hearts when you draw two cards randomly out of a deck of cards? (order doesn't matter)
13 choose 2 over 52 choose 2 = 1 / 17
There 20 marbles in a bucket, among them there are 4 red and 4 black. What is the probability of not getting red or black?
11 / 20
Decide if the statement is true or false. Prove your answer.
The probability that the sum of the numbers on two dice will be 6 and 8 is the same.
true, we can roll both 6 ( 1 + 5, 2 + 4, 3 + 3) and 8 (2 + 6, 5 + 3, 4 + 4) in five ways
There are 10 English and 12 German students in a class of 22 students. What is the probability of choosing an English and a German student if we choose two randomly?
10 x 12 / 22 choose 2 = 40 / 77 = 0.519
8
What is the probability of drawing the queen of hearts first and than the ace of spades?
1 / 52 x 1 / 51 = 1 / 2652
There are 6 white marbles in a bucket. How many red marbles do I have to add so that the probability of choosing red is 0.625?
10
What is the probability that the sum of the numbers on two dice will be at least 9?
10 / 36
There are 10 English and 12 German students in a class of 22 students. 4 of them are going to a competition. What is the probability that there will be as many English students as German students on the team?
10 choose 2 x 12 choose 2 / 22 choose 4 = 54 / 133 = 0.41
How many teeth does an adult human have?
32
What is the probability of drawing two red cards and two black cards when drawing 4 cards randomly? (order doesn't matter)
26 choose 2 x 26 choose 2 over 52 choose 4 = 825 / 833 = 0.39
In a bucket there are 4 red, 5 black and 10 white marbles. If we draw three marbles, what is the probability that the first will be red, the second will be black and the third is white?
4 / 20 x 5 / 19 x 10 / 18 = 5 / 171 = 0.029
If we roll a die 3 times, what is the probability that we will roll first 1, then 2 then 3?
1 / 6 x 1/ 6 x 1/6 = 1 / 216
There are 10 English and 12 German students in a class of 22. We take 6 to a competition. What is the probability that we will take exactly 4 English students?
(10 choose 4 x 12 choose 2) / 22 choose 6 = 60 / 323 = 0.1857
The actor who plays Captain America
If we draw 3 cards, what is the probability that there will be at least one red and one black? (order doesn't matter)
((26 choose 2 x 26) + (26 x 26 choose 2)) / 52 choose 3 = 13 / 17 = 0.76
In a bucket there are 5 white marbles and 6 black marbles. If I choose 4, what is the probability that amond the chosen ones there will be as many white as black marbles?
(5 choose 2 x 6 choose 2) / 11 choose 4 = 5 / 11 = 0.45
Anne and Bob are playing a game. They roll a die two times and add the numbers. Anna wins if the sum is a prime number, Bob wins otherwise. Who has better chances of winning? Why?
Bob, probability : 21 / 36
There are 10 English and 12 German students in a class of 22. We take 6 to a competition. What is the probability that we will take at least 4 English students?
((10 choose 4 x 12 choose 2) / 22 choose 6) + ((10 choose 5 x 12 choose 1) / 22 choose 6) + ((10 choose 6 x 12 choose 0) / 22 choose 6) = 74 / 323= 0.23
The stapes, the smallest bone in the human body, is found where?
Ear