# Probability + multiplication principle - examples

Probability is the measure of the likeliness that an event will occur. The probability (chance) is a value from the interval <0;1> or in percentage (0% to 100%) expressing the occurrence of some event. 0 is impossible event and 1 (100%) means the certainty event.

1. Boys and girls
There are 11 boys and 18 girls in the classroom. Three pupils will answer. What is the probability that two boys will be among them?
2. Word
What is the probability that a random word composed of chars T, H, A, M will be MATH?
3. Balls
From the urn in which are 7 white balls and 17 red, gradually drag 3-times without replacement. What is the probability that pulls balls are in order: red red red?
4. Events
Event N has probability of 0.24. What is the probability that the event N occurs in 8, 5, 4 try.
5. Pizza
A school survey found that 12 out of 15 students like pizza. If 6 students are chosen at random, what is the probability that all 6 students like pizza?
6. Hockey players
After we cycle five hockey players sit down. What is the probability that the two best scorers of this crew will sit next to each other?
7. Components
In the box are 8 white, 4 blue and 2 red components. What is the probability that we pull one white, one blue and one red component without returning?
8. Hearts
4 cards are chosen from a standard deck of 52 playing cards (13 hearts) with replacement. What is the probability of choosing 4 hearts in a row?
9. Dices throws
What is the probability that the two throws of the dice: a) Six falls even once b) Six will fall at least once
10. travel agency
Small travel agency offers 5 different tours at honeymoon. What is the probability that the bride and groom choose the same tour (they choose independently)?
11. Green - Red
We have 5 bags. Each consist one green and 2 red balls. From each we pull just one ball. What is the probability that we doesn't pull any green ball?
12. Throw
We throw 2 times with 2 dices. What is the probability that the first roll will fall more than sum of 9 and the second throw have sum 3 or does not have the sum 4?
13. Sum or product
What is the probability that two dice fall will have the sum 7 or product 12?
14. Cards
From a set of 32 cards we randomly pull out three cards. What is the probability that it will be seven king and ace?
15. Probability
What are the chances that the lottery, in which the numbers are drawn 5 of 50 you win the first prize?
16. Six on dice
What is the probability that when throwing two dice will fall at least one six?
17. Two aces
From a 32 card box we randomly pick 1 card and then 2 more cards. What is the probability that last two drawn cards are aces?
18. Dice
We throw five times the dice. What is the probability that six fits exactly twice?
19. Boys and girls
There are eight boys and nine girls in the class. There were six children on the trip from this class. What is the probability that left a) only boys b) just two boys
20. Dice
We throw 10 times a play dice, what is the probability that the six will fall exactly 4 times?

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