Help pls with probability tasks.
1.In the class, there are 14 girls and 9 boys. Let's consider event A - there are at least two girls in the class who were born in the same month. Event A is...
A. an impossible event
C. an elementary event
B. a certain event
D. impossible to determine
2.There are 75 parts in the box, each labeled with a number from 1 to 75. Among these parts, 10 are defective. Let's consider event B - taking out a part with the number 10 from the box. Event B is...
A. an impossible event
B. a certain event
C. an elementary event
D. impossible to determine
3.Out of 25 shots, 20 hit the target. The relative frequency of hits is...
A. 5/25
B. 5/20
C. 25/20
D. 20/25
4.In a certain month, 43 boys and 57 girls were born. The relative frequency of boys born in that month is...
A. 43/57
B. 57/43
C. 43/100
D. 57/100
5.There are twelve balls in a jar, labeled with numbers from 1 to 12. The probability that drawing a ball will result in a number divisible by 3 is...
A. 1/12
B. 1/4
C. 1/3
D. 1/2
6.The probability that a part is of good quality is 0.75. Calculate the probability that it is not of good quality.
A. 0.25
B. 1
C. 0.75
D. 0.25/0.75
7.Two coins are flipped. The probability that at least one coin lands heads up is...
A. 0.25
B. 0.5
C. 0.75
D. 1
8.A fair die is rolled. The probability of rolling a 2 is...
A. 1/6
B. 5/6
C. 1/3
D. 2/3
9.From a deck of cards containing 36 cards, one card is drawn. Calculate the probability that the drawn card is a spade.
A. 1/4
B. 1/6
C. 1/9
D. 1/36
10.There are 2 white and 8 black marbles in a bag. Calculate the probability of randomly selecting a white marble.
A. 1/5
B. 1/4
C. 3/4
D. 1/36
11.Two dice are rolled. Calculate the probability that the sum of the numbers rolled is 5.
A. 1/36
B. 1/9
C. 5/36
D. 1/6
12.Jānis usually throws a ball into the basket with a probability of 0.68. Calculate how many times he will throw the ball into the basket if he makes 50 throws.
A. 8
B. 16
C. 34
D. 0.44
13.Two dice are rolled. The probability that at least one of them shows 4 points is...
A. 1/6
B. 1/9
C. 11/36
D. 1/3
14.A worker regulates two independent machines. The probability of needing to regulate the first machine within an hour is 0.8, and for the second machine it is 0.7. Calculate the probability that both machines need to be regulated within an hour.
A. 0.44
B. 0.56
C. 0.2
D. 0.3
15.Targets are arranged in two concentric rings with radii R and 4R. It is known that a shot hit the target. Calculate the probability that the shot hit the smaller ring.
A. 1/4
B. 1/3
C. 1/16
D. 1/9
16.In a lottery with 20 tickets, 4 tickets are winning tickets. Ilze buys one ticket. Calculate the probability that her ticket is a winning ticket.
A. 1/4
B. 1/5
C. 1/20
D. 4/5
17.Two friends meet. Calculate the probability that both of them were born on a Saturday.
A. 1/7
B. 2/7
C. 2/49
D. 1/49
18.A student has learned 7 out of 8 questions. In a test, two of these questions will be included. Calculate the probability that the student knows both of these questions.
A. 7/8
B. 49/56
C. 42/64
D. 3/4
19.There are 4 cards in an envelope labeled with the letters A, P, S, E. Successively, three cards are drawn from the envelope without replacement. Calculate the probability that the cards are drawn in the order A, P, E.
A. 1/6
B. 1/12
C. 1/24
D. 3!/4!
20.Two dice are rolled simultaneously. Calculate the probability that the sum of the numbers rolled is 14.
A. 1
B. 14/36
C. 1/36
D. 0
