Combinatorics - math word problems

Number of problems found: 405

  • Sales
    tesco From statistics of sales goods, item A buy 51% of people and item B buys 59% of people. What is the probability that from 10 people buy 2 item A and 8 item B?
  • Events
    items Event P has probability of 0.84. What is the probability that the event P occurs in 3, 5, 7 try.
  • Pediatrician
    doctor Pediatrician this month of 20 working days takes 8 days holidays. What is the probability that on Monday it will be at work?
  • TV fail
    old_tv The TV has after 10,000 hours average 35 failures. Determine the probability of TV failure after 400 hours of operation.
  • Lines
    lines In how many points will intersect 14 different lines, where no two are parallel?
  • 7 heroes
    7statocnych 9 heroes galloping on 9 horses behind. How many ways can sort them behind?
  • Bureau of Labor
    UPSVAR Bureau of Labor is a state institution that provides mike and the rest for their so-called clients. The mission of the Bureau of Labor is spend taxpayer money to provide relaxation and benefits to those who do not want to work. Popularly speaking sense th
  • Rectangle
    diagonal In a rectangle with sides, 8 and 9 mark the diagonal. What is the probability that a randomly selected point within the rectangle is closer to the diagonal than to any side of the rectangle?
  • Raffle
    tombola_tickets In the pool is numbers from 1 to 115. What is the probability that a randomly selected number is not a prime number?
  • Hockey
    hokej The hockey match ended 8:2. How many different matches could be?
  • Calculation of CN
    color_combinations Calculate: (789 choose 786) - (789 choose 3)
  • Subsets
    1venna_sets How many are all subsets of set C = (97, 67, 66, 18, 59, 64)?
  • Word
    words What is the probability that a random word composed of chars E, Y, G, E, R, O, M, T will be the GEOMETRY?
  • Bulbs
    bulbs In the box are 6 bulbs with power 75 W, 14 bulbs with power 40 W and 15 with 60 W. Calculate probability that a randomly selected bulb is:
  • Rectangles
    rectangles How many rectangles with area 8713 cm2 whose sides are natural numbers are?
  • Flags
    vlajka_cz How many different flags can be made from colors red, yellow, blue, green, white to consist of three different colors?
  • Shooter
    terc The probability that a good shooter hits the center of the target circle I is 0.1. The probability that the target hit intercircle is II 0.58. What is the probability that it hits the target circle I or II?
  • Shooters
    soldiers In army regiment are six shooters. The first shooter target hit with a probability of 49%, next with 75%, 41%, 20%, 34%, 63%. Calculate the probability of target hit when shooting all at once.
  • Event probability
    dices The probability of event P in 8 independent experiments is 0.33. What is the probability that the event P occurs in one experiment (chance is the same)?
  • Bulbs
    bulb 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?

Do you have an exciting math question or word problem that you can't solve? Ask a question or post a math problem, and we can try to solve it.



We will send a solution to your e-mail address. Solved examples are also published here. Please enter the e-mail correctly and check whether you don't have a full mailbox.

Please do not submit problems from current active competitions such as Mathematical Olympiad, correspondence seminars etc...



Would you like to compute count of combinations?