Combinatorics - practice problems - page 3 of 52
Number of problems found: 1030
- 3 sigma
Students' performance scores in a statistic test have a mean of 70 and a standard deviation of 4.0. The scores obtained can be modeled by a normal distribution. Find the probability that the score of a randomly selected student is i. more than 80 marks ii - Containers
One in eight containers is temporarily misplaced. A random sample of 12 containers is selected. What is the probability that 6 of these containers will be temporarily misplaced? - 3 pens
3 pens are to be taken from a bunch of 100 pens.If 10 pens are defective, find probability of getting all good pens. - Bulb life
Tests show that the lives of light bulbs are normally distributed with a mean of 750 hours and a standard deviation of 75 hours. Find the probability that a randomly selected light bulb will last between 675 and 900 hours.
- And or logic
If A and B are events with P(A)=0.3, P(A OR B)=0.76, and P(A AND B)=0.04, find P(B). Enter your answer in decimal form, rounded to one place. - The profit 3
An investment's profit (or loss) is normally distributed with a mean of $11,200 and a standard deviation of $8,250. What is the probability of a loss rather than a profit? - And - or probability rules
Given P(A)=0.4, P(B)=0.56, and P(A and B)=0.274, find the value of P(A or B), rounding, if necessary. - Triangles - segments
How many triangles can be formed with segments measuring one and 2/3 mm one 3/4 mm and 2 1/2 mm - Fish service
According to a report by the U. S. Fish and Wildlife Service, the mean length of six-year-old rainbow trout in the Arolik River in Alaska = 484.6 millimeters with a standard deviation = 31.2 millimeters. Assume these lengths are normally distributed. What
- Ekene and Amina
The probability that Ekene will be alive in 5 years' time is 3/4, and the probability that his wife Amina will be alive in 5 years' time is 2/5. Find the probability that in 5 years' time: a) both of them will be alive b) only Ekene will be alive - Family survey A total of 160 families with 4 children each were surveyed with the following results. Boys; 4; 3; 2; 1; 0 Girls ; 0; 1; 2; 3; 4 Families; 7; 50; 55; 32; 16 Let the probability of picking a boy or a girl be 1/2. Let P=boy, Q=girl. What is the probability
- Repairs
A small repair shop orders parts for its repairs. Its supplier claims that only 2% of its parts are defective. In order of 500 parts, an employee takes a sample of 100 parts. Determine the likelihood that the employee finds three or more parts are defecti - Drunken drivers
40% of drivers driving between 11 pm and 5 am are drunken drivers. In a random sample of 20 drivers driving between 11 pm and 5 am, find the probability that: A) Exactly 12 will be drunken drivers B) At least 7 will be drunken drivers C) At most 5 will be - A random 2
A random sample of 40 families has an average water consumption of 29 cubic meters per month, with a sample standard deviation of 8 cubic meters. Give the 90% confidence interval for the mean usage of water per month.
- A disease A disease affects 10% of the individuals in a population, and a sample of 100 people was selected from the population. What is the probability of finding the disease in at least 15 people?
- Defect rate
A manufacturing machine has a 3% defect rate. If 9 items are chosen randomly, what is the probability that at least one will have a defect? - Repeatition not allowed
How many four-digit numbers can be formed from the numbers 3 5 8 9 if they are not allowed to be repeated? - Celebration 83607
Five boys and five girls were nominated for a celebration at a local school. How many ways can the prom king, prom queen, and two other students be chosen from those nominated? (The king must be a boy, and the queen must be a girl) - Playmakers 83340
In a basketball game, two pivots, two wings, and one point guard play. The coach has three pivots, four wing players, and two playmakers available on the bench. How many different five players can a coach send to the board during a game?
The grandfather bought 10 rubbers for 10 grandchildren. In the bag were 3 blue, 2 green and the rest red. Hansel would like blue gum. What is the probability that Janek will draw a blue rubber if 2 cousins have already drawn it before him and drawn blue aDo you have homework that you need help solving? Ask a question, and we will try to solve it. Solving math problems.
