Permutations - problems
- Boys and girls
There are eight boys and nine girls in the class. There were six children on the trip from this class. What is the probability that left a) only boys b) just two boys
- Inverted nine
In the hotel,, Inverted nine" each hotel room number is divisible by 6. How many rooms we can count with three-digit number registered by digits 1,8,7,4,9?
- 7 heroes
9 heroes galloping on 9 horses behind. How many ways can sort them behind?
How many different flags can be made from colors purple, yellow, red, white, blue, green, orange so that each flag consisted of three different colors?
In how many ways can 7 shuttle vans line up at the airport?
What is the probability that a random word composed of chars T, H, A, M will be MATH?
How many ways are there to arrange 6 books on a shelf?
- Phone numbers
How many 9-digit telephone numbers can be compiled from the digits 0,1,2,..,8,9 that no digit is repeated?
How many rectangles with area 3002 cm2 whose sides is natural numbers are?
- Playing cards
How many possible ways are to shuffle 7 playing cards?
At the table sit 8 people, 4 on one side and 4 on the other side. Among them are 3 pairs. Every pair wants to sit opposite each other. How many ways can they sit?
Combination lock will open when the right choice of 3 numbers (from 1 to 25 inclusive) is selected. A. How many different lock combinations are possible? B. Is he combination lock named appropriately?
How many diagonals has convex 11-gon?
How many are all subsets of set ??
How many different ways can sit 8 boys and 3 girls in line, if girls want to sit on the edge?
- Hockey players
After we cycle five hockey players sit down. What is the probability that the two best scorers of this crew will sit next to each other?
- School trip
Class has 17 students. What different ways students can be accommodated in the hostel, where available 3× 2-bed, 1× 3-bed and 2× 4-bed rooms. (Each room has its own unique number)
How many different 7 digit natural numbers in which no digit is repeated, can be composed from digits 0,1,2,3,4,5,6?
3 children pulled 12 different toys from a box. Many ways can be divided toys so that each children had at least one toy?
How many ways can select 4 fields on classic chess board with 64 fields, so that fields don't has the same color?
See also our permutations calculator.