Percentages + combinatorial number - practice problems
Number of problems found: 31
- 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? - 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? - Competition 82310
In the shooting competition, each shooter fires 5 shots. Shooter Muška will hit the target with one shot with a probability of 60%. What is the probability that he hits at least once out of five shots? - Probability 81677
The probability that a plant will grow from a seed is 75%. What is the probability that 5 plants will grow if we assemble 6 seeds?
- Questions 81676
You will learn 50% of the 30 questions. If I get 4 questions, I'll know 3. - Effectiveness 80811
According to clinical studies, the effectiveness of the drug is 90%. The doctor prescribed the medicine to eight patients. What is the probability that the drug will be effective in all these patients? - Manufacturer 80810
The manufacturer indicates that the germination rate of the pepper seeds is 68%. What is the probability that a) out of ten seeds sown, at least 8 will germinate? b) will at most 3 sprouts out of ten seeds be sown? - Yarhands
Yarhands statistical consult conducted statistical analysis on the election results from 1992 to 2012 to assess the chances of the NPP winning the election in Ghana's Volta region. The research reveals that 15% of inhabitants in the Volta region favor the - Probability 69914
During the exam, each student receives 30 different questions, from which he chooses 3 at random. To pass the exam, he needs to be able to answer two correctly. What is the probability that a student will pass if he mastered 70% of the questions (70% of t
- Created trio
What is the probability that in the created trio, which consists of 19 boys and 12 girls, they will be: a) the boys themselves b) the girls themselves c) 2 boys and one girl? - Covid-19
Data showed that 22% of people in a small town were infected with the COVID-19 virus. A random sample of six residents from this town was selected. Find the probability that exactly two of these residents were infected. - Doctors
The drug successfully treats 90% of cases. Calculate the probability that it will cure at least 18 patients out of 20. - Wimbledon finals
Serena Williams made a successful first serve 67% 0f the time in a Wimbledon finals match against her sister Venus. If she continues to serve at the same rate the next time they play and serves six times in the first game, determine the probability that: - Probability 30271
The probability of an adverse drug reaction is 2.1%. How many people need to be prescribed for one patient to experience side effects with a chance of 90%?
- Hazard game
In the Sportka hazard game, six numbers out of 49 are drawn. What is the probability that we will win: a) second prize (we guess five numbers correctly) b) the third prize (we guess four numbers correctly)? - Manufacturer 24801
With a repeat check, five hundred of the series of products are to be inspected. The manufacturer guarantees 2% scrap for a given production. Determine the probability of scraps among the 500 products reviewed between 12 and 20. - All use computer
It is reported that 72% of working women use computers at work. Choose three women at random, and find the probability that all three women use a computer in their jobs. - Sick days
In Canada, there are typically 261 working days per year. There is a 4.9% chance of an employee taking a sick day. What is the probability an employee will use 17 OR MORE sick days in a year? - STRESSED word
Each letter in STRESSED is printed on identical cards, one letter per card, and assembled in random order. Calculate the probability that the cards spell DESSERTS when assembled.
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Our percentage calculator will help you quickly calculate various typical tasks with percentages. See also our combinations calculator. Percentages practice problems. Combinatorial number - practice problems.