What Is a Combination?
Read this topicExplanations 4
- Let's look at an example first. Suppose there are 777 people and we have to form a committee of 333 people out of these 777. (In the committee all 333 have equal power!) Let's t…
By Neelarnab Raha, Ruiran Xun, Anusha Rahman
- The number of combinations of rrr objects out of a set of nnn is given by the formula (nr)=n!r!(n−r)!\binom{n}{r} = \frac{n!}{r!(n-r)!}(rn)=r!(n−r)!n! You might also see combi…
By Ruiran Xun, Anusha Rahman
- (Video) Combinations made easy by tecmath Check out this video by tecmath to learn more about combinations! ##Combinations According to the video, combinations are specifically …
By Trisha, Anusha Rahman
- Combination Formula In combinations, the arrangement or order of the elements selected does not matter. The order of the selection does not matter. That means that if you select…
By Anusha Rahman
Problems 8
- There are 141414 students in a class. In how many different ways can the students be divided in two groups containing 888 and 666 students, respectively? Write your answer as a …
- Suppose f(x)=ax2+bx+cf(x) = ax^2+bx+cf(x)=ax2+bx+c is a quadratic such that f(n)f(n)f(n) is an integer for every integer nnn. Among such quadratics, what is the smallest possibl…
- A coin that comes up heads with probability p>0p > 0p>0 and tails with probability 1−p>01-p > 01−p>0 independently on each flip is flipped eight times. Suppose the probability o…
- Four different positive integers less than 101010 are chosen randomly. What is the probability that their sum is odd? Write your answer as a fraction ab\frac{a}{b}ba in lowest …
- How many triangles are there in the figure above?
- There are 121212 points in a plane with no three points collinear. (a) How many straight lines can be determined from these points? (b) How many triangles can be drawn using any…
- There are 141414 students in a class. In how many different ways can the students be divided in two groups each containing 777 students?
- What is the minimum total number of frequencies that one could use to design an alternative system, in which each digit from 0 to 9 is represented by some pair of frequencies, b…