# Probability + combinatorial number - math problems

#### Number of problems found: 47

• Probability of failures In certain productions, the probability of failures is 0.01. Calculate the probability that there will be more than 1 failure among the 100 selected products if we return the selected products to the file after the check.
• Dice We throw five times the dice. What is the probability that six fits exactly twice?
• Dice We throw 10 times a play dice, what is the probability that the six will fall exactly 4 times?
• Word What is the probability that a random word composed of chars E, Y, G, E, R, O, M, T will be the GEOMETRY?
• Cards The player gets 8 cards of 32. What is the probability that it gets a) all 4 aces b) at least 1 ace
• Bulbs The probability that the bulb can operate 4000 hours is 0.3. What is the probability that exactly one of eight bulbs can operate 4000 hours?
• Probability of malaria A survey carried out at a certain hospital indicates that the probability that a patient tested positive for malaria is 0.6. What is the probability that two patients selected at random (i) one is negative while the other tested positive? (i) both patient
• Cards From a set of 32 cards we randomly pull out three cards. What is the probability that it will be seven king and ace?
• travel agency Small travel agency offers 5 different tours at honeymoon. What is the probability that the bride and groom choose the same tour (they choose independently)?
• Sum or product What is the probability that two dice fall will have the sum 7 or product 12?
• One green In the container are 45 white and 15 balls. We randomly select 5 balls. What is the probability that it will be a maximum one green?
• Family 94 boys are born per 100 girls. Determine the probability that there are two boys in a randomly selected family with three children.
• Three students Three students independently try to solve the problem. The first student will solve a similar problem with a probability of 0.6, the second student will solve at a probability of 0.55, and the third will solve at a probability 0.04. The problem is resolve
• Three reds What is the probability that when choosing 3 carats from seven carats, all 3 reds will be red?
• Balls The urn is 8 white and 6 black balls. We pull 4 randomly balls. What is the probability that among them will be two white?
• Records Records indicate 90% error-free. If 8 records are randomly selected, what is the probability that at least 2 records have no errors?
• Family What is the probability that a family with 7 childrens have: exactly 5 girls? 7 girls and 0 boys? Consider the birth probability of a girl is 48.69% and boy 51.31%.
• Seeds The germination of seeds of a certain species of carrot is 96%. What is the probability that at least 25 seeds out of 30 will germinate?
• Playing cards From 32 playing cards containing 8 red cards, we choose 4 cards. What is the probability that just 2 will be red?
• Families 2 Seven hundred twenty-nine families are having six children each. The probability of a girl is 1/3, and the probability of a boy is 2/3. Find the number of families having two girls and four boys.

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