# Combinatorics - math word problems - last page

Combinatorics is a part of mathematics that investigates the questions of existence, creation and enumeration (determining the number) of configurations.It deals with two basic tasks:

How many ways can we select certain objects

How many ways can we arrange certain objects

#### Number of problems found: 1018

- Birthday paradox

How large is the group of people so that the probability that two people have a birthday on the same day of the year is greater than 90%? - Probability 7628

The probability that six will fall in just three rolls is once? - 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. - Three shooters

Three shooters shoot, each time, on the same target. The first hit the target with 0.7, the second with 0.8, and the third with 0.9 probability. What is the probability of hitting the target: a) just once b) at least once c) at least twice

- Three-digit 58943

The vortex of the three given digits formed different three-digit numbers. When she added up all these numbers, she published 1554. What numbers did Vierka use? - Seeds

From a box of spruce seeds with a germination of 80%, we randomly selected ten seeds and planted them. Find the median of the random variable: the number of germinating seeds. - Probability 71174

Find the probability that one will fall at least once in three rolls. - Three-digit 7248

Find all three-digit numbers n with three different non-zero digits divisible by the sum of all three two-digit numbers we get when we delete one digit in the original number. - Poisson distribution - daisies

The meadow behind FLD was divided into 100 equally large parts. Subsequently, it was found that there were no daisies in ten of these parts. Estimate the total number of daisies in the meadow. Assume that daisies are randomly distributed in the meadow.

- Rectangle 82087

A 9cm × 15cm rectangle is divided into unit squares. How many paths are there from one rectangle vertex to the opposite vertex if one can only go to the right and up the sides of the squares? - Distribution 6283

The life of the bulbs has a normal distribution with a mean value of 2000 hours and a standard deviation of 200 hours. What is the probability that the light bulb will last for at least 2100 hours? - Intersect 5216

At how many points do ten lines intersect if no two are parallel? - Eight blocks

Dana had the task of saving the eight blocks of these rules: 1. Between two red cubes must be a different color. 2. Between two blue must be two different colors. 3. Between two green must be three different colors. 4. Between two yellow blocks must be fo - Book Store

The Mabini Book Store (MBS) is reducing the prices of Mathematics books for promotion. The store has 6 Algebra books, 6 Geometry books, and 5 Statistics books to be arranged on a shelf. Books of the same kind are to be placed beside each other. How many w

- Probability 59493

Determine the probability of a random event out of 10 randomly selected bridge cards. There will be at least three aces. Note This is a team game, with 52 cards in the deck, of which four aces. - 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? - Probability 37651

What is the probability that in a family with four children, there are: a) at least three girls b) at least one boy, If the probability of a boy is 0.51? - Records

Records indicate 90% error-free. If eight records are randomly selected, what is the probability that at least two records have no errors?

Do you have homework that you need help solving? Ask a question, and we will try to solve it.