Combinatorial number - examplesSee also our combinations calculator.
- Sum on dice
We have two dice. What is the greater likelihood of fall a total sum 7 or 8 ? (write 7, 8 or 0 if the probabilities are the same)?
- Sum or product
What is the probability that two dice fall will have the sum 7 or product 12?
How many lines can be draw with 8 points, if three points lie on one line and the other any three points do not lie on the same line?
What is the probability that a random word composed of chars T, I, O, D, I will be IDIOT?
In the market have 3 kinds of chocolates. How many ways can we buy 13 chocolates?
How many rectangles with area 2832 cm2 whose sides is natural numbers are?
From statistics of sales goods, item A buy 54% of people and item B buys 58% of people. What is the probability that from 3 people buy 2 item A and 1 item B?
How many ways can divide 22 identical candies to 4 children?
Annie has a total of $ 435. The money must be divided into stacks so that each buyer has the same amounth of dollars. How many options she have?
How many diagonals has convex 29-gon?
At party overyone clink with everyone. Together, they clink 406 times. How many people were at the party?
- 2nd class combinations
From how many elements you can create 1081 combinations of the second class?
In how many points will intersect 11 different lines, where no two are parallel?
From the five girls and four boys teachers have to choose one pair of boy and girl. A) How many such pairs of (M + F)? B) How many pairs where only boys (M + M)? C) How many are all possible pairs?
A class consists of 5 males and 18 females. How many committees of 4 are possible if the committee must consist of 3 males and 1 females?
What is the probability that a family with 7 childrens have: exactly 0 girls? 1 girl and 6 boys? Consider the birth probability of a girl is 48.73% and boy 51.27%.
The probability that the bulb can operate 4000 hours is 0.13. What is the probability that exactly one of eight bulbs can operate 4000 hours?
The class is 22 students. How many ways can choose four to examination?
Determine how many ways can be chosen four representatives from 27 students to school tournament.
- The camp
At the end of the camp a 9 friends exchanged addresses. Any friend gave remaining 8 friends his card. How many addresses they exchanged?