Combinations Calculator
The calculator finds the number of combinations of the k-th class from n elements without repetition. A combination without repetition of k objects from n is a way of selecting k objects from a list of n. The order of selection does not matter and each object can be selected once (without repetition).Calculation:
Ck(n)=(kn)=k!(n−k)!n! n=10 k=4 C4(10)=(410)=4!(10−4)!10!=4⋅3⋅2⋅110⋅9⋅8⋅7=210
The number of combinations: 210
A bit of theory - the foundation of combinatorics
Combinations
A combination of the k-th class of n elements is an unordered k-element group formed from a set of n elements. The elements are not repeated and the order does not matter. In mathematics, such unordered groups are called sets and subsets. The count is called a combination number and is calculated as follows:Ck(n)=(kn)=k!(n−k)!n!
A typical example: we have 15 students and need to choose 3. How many ways can this be done?
Foundation of combinatorics in word problems
- Classroom
Of the 26 pupils in the classroom, 12 boys and 14 girls, four representatives are picked to the odds of being: a) all the girls b) three girls and one boy c) there will be at least two boys - The chief
The chief fisherman, Peter, estimates that if he uses four lines, then the probability of making a catch on one line is 0.7. If he uses five lines, then the probability of making a catch on any line is 0.6. If he uses six lines, the probability of making - One green
There are 45 white and 15 green balls in the container. We randomly select five balls. What is the probability that there will be one green ball maximally? - Plane count
There are 12 points in space, with no three lying on a straight line. How many different planes are determined by these points? - Electricity
Many companies providing public utility services promote energy saving by offering discount rates for consumers who keep their energy consumption below certain set standards. A recent EPA report states that 70% of the inhabitants of a monitored region red
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