Test: Probability I - Normal

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Question 1:   The box fits 15 different items:   7 pencils and 8 pens. 3 pencils and 5 pens are taken off the box randomly. How many elementary consequences are possible here?
C 7 3 + C 8 5
8!
C 15 8
C 7 3 × C 8 5
Question 2:   During the exam session, professor graded his students' tests. Out of 100 students, 15 got "A", 28 got "B", 40 got "C", 17 students failed the test. What was the probability p A not to fail this test?
0.83
0.15
0.5
0.17
Question 3:   There are 6 blue and 9 red pens in the box. What is the least amount of pens you should randomly pick to pick a blue pen with guarantee?
1
10
15
6
Question 4:   A group of scientists are providing an experiment on simultaneous tossing of 5 coins. The result of the experiment is the final amount of tails that will drop out. How many possible consequences can be at the end of this experiment?
5
3
10
6
Question 5:   After some calculations, it was determined that the probability of hitting the target is 25% . Is it possible that after 100 shots there will be 98 hits?
Yes
Yes, only if number of hits will increase.
No
Yes, only if probability of hitting the target is increased.
Question 6:   Two six-sided dices are being tossed at the same time - blue one and yellow one. What is the probability that the sum of numbers on both dices will be 11 ?
1 36
2 18
1 18
11 12
Question 7:   In the batch of 100 produced bricks, 5 are defective. What is the when all 8 randomly picked bricks would be non-defective?
C 100 95
C 95 8 C 100 8
C 95 8
C 95 8 C 100 8
Question 8:   A basketball player shoots three-pointers with probability of 40% to the basket. What is the probability that he will hit only one time of three shots?
40%
13.33%
20%
14.4%
Question 9:   Jack has 10 cards and Bill has 8 . In how many ways they can exchange 2 Jack's cards for 2 Bill's cards?
C 10 2 × C 8 2
A 18 4
80
C 18 4
Question 10:   What is the probability of that the randomly named natural number would be negative?
0
0.5
1
1