Probability

1103158402

Level: 
C
We roll red and yellow dice. Let the event A be: On the red die a number greater than 2 is rolled. And let the event B be: The sum of points rolled on both dice is greater than 6. Find P(A|B). (Note: In the table the sums of points on both dice are listed.)
34
12
67
14

1003029305

Level: 
B
The production process of a particular component consists of three independent phases. Through long-term monitoring of production quality were found success rates of individual phases 90%, 80% and 85%. If all three phases of the process are successful, the component is of good quality. What is the probability of producing a good quality component?
0.612
0.003
0.388
0.997

1003029302

Level: 
B
The quality inspection found that 85% of the items are without defect, exactly one defect has 10% of the items, and the other items have more than one defect. We pick one item randomly. What is the probability that this item has at least one defect?
0.15
0.10
0.95
0.01

1003029206

Level: 
C
In the hospital, 22 boys and 18 girls were born in one month. Babies were listed in the register by their date of birth. Find the probability that there are at least three boys in the first five places of the register. The results are rounded to four decimal places.
(223)(182)+(224)(181)+(225)(180)(405)=0.5982
(223)+(224)+(225)(405)=0.0535
223182+224181+225180405=0.1252
(223)(182)+(224)(181)+(225)(180)405=0.0038

1003029205

Level: 
C
In the hospital, 22 boys and 18 girls were born in one month. Babies were listed in the register by their date of birth. Find the probability that there are two boys and three girls in the first five places of the register. The results are rounded to four decimal places.
(222)(183)(405)=0.2865
(222)(183)40!35!=0.0024
222183405=0.0276
(223)(182)40!35!=0.0030

1003029204

Level: 
C
A class consists of 50 students including twins, Mark and Martin. For an exam students are randomly divided into two equally sized subgroups. Find the probability that Mark and Martin will be in the same subgroup. The results are rounded to two decimal places.
(4823)+(4825)(5025)=0.49
(4823)(5025)=0.24
2(4824)(5025)=0.51
(4924)(5025)=0.50