Combinatorial number - examples - page 4
15 boys and 10 girls are in the class. On school competition of them is selected 6-member team composed of 4 boys and 2 girls. How many ways can we select students?
If the number of elements increase by 3, it increases the number of combinations of the second class of these elements 5 times. How many are the elements?
- Points in plane
The plane is given 12 points, 5 of which is located on a straight line. How many different lines could by draw from this points?
How many elements can form six times more combinations fourth class than combination of the second class?
We throw five times the dice. What is the probability that six fits exactly twice?
We throw 10 times a play dice, what is the probability that the six will fall exactly 4 times?
There are 200 draws in the raffle, but only 20 of them win. What is the probability of at least 4 winnings for a group of people who have bought 5 tickets together?
The teacher prepared a test with ten questions. The student has the option to choose one correct answer from the four (A, B, C, D). The student did not get a written exam at all. What is the probability that: a) He answers half correctly. b) He answers.
Five sticks with a length of 2,3,4,5,6 cm. How many ways can you choose three sticks to form three sides of a triangle?
- Three students
Three students independently try to solve the problem. The first student will solve a similar problem with a probability of 0.6, the second student will solve at a probability of 0.55, and the third will solve at a probability 0.04. The problem is resolved
What x-gon has 54 diagonals?
How many 19 element's subsets can be made from the 26 element set?
- Combinations 6
6 purses 9 flaps 12 straps Every combination must include 1 purse, 1 flap and 1 strap. How many possible combinations?
- Bridge cards
How many bridge hands are possible containing 4 spades,6 diamonds, 1 club, and 2 hearts?
- Cancel fractions
Compress the expression of factorial: (n+6)!/(n+4)!-n!/(n-2)!
- Find the 2
Find the term independent of x in the expansion of (4x3+1/2x)8
There are 9 interactive basic building blocks of an organization. How many two-blocks combinations are there?
See also our combinations calculator.