Combinatorics - problemsWould you like to compute count of combinations?
What is the probability that a random word composed of chars T, I, O, D, I will be IDIOT?
- Football league
In the 2nd football league is 19 teams. How many ways can be filled first, second and third place?
Event J has probability of 0.17. What is the probability that the event J occurs in:
How many different ways can sit 5 boys and 5 girls in line, if girls want to sit on the edge?
- Seating rules
In a class are 22 seats but in 2.B class are only 14 students. How many ways can student seat? (The class has 11 benches. A bench is for a pair of students.) Result (large number) logarithm and thus write down as powers of 10.
- The dice
What is the probability of events that if we throw a dice is rolled less than 6?
How many different combinations of two-digit number divisible by 4 arises from the digits 3, 5 and 7?
- 7 heroes
5 heroes galloping on 5 horses behind. How many ways can sort them behind?
- 2nd class variations
From how many elements you can create 6480 variations of the second class?
- Two doctors
Doctor A will determine the correct diagnosis with a probability 80% and doctor B with a probability 72%. Calculate probability of correct diagnosis if patient is diagnosed by both doctors.
- Playing cards
How many possible ways are to shuffle 7 playing cards?
A school survey found that 9 out of 16 students like pizza. If 5 students are chosen at random, what is the probability that all 5 students like pizza?
- Area codes
How many 6 digit area codes are possible if the first number can't be zero?
- Cars plates
How many different licence plates can country have, given that they use 3 letters followed by 4 digits?
- Count of triangles
Given a square ABCD and on each side 8 internal points. Determine the number of triangles with vertices at these points.
The city has 7 fountains. Works only 6. How many options are there that can squirt ?
How many different ways can initiate a game of chess (first pass)?
We test medicine on 6 patients. For all drug doesn't work. If the drug success rate of 20%, what is the probability that medicine does not work?
I have 7 cups: 1 2 3 4 5 6 7. How many opportunities of standings cups are there if 1 and 2 are always neighborhood?
Find all five-digit numbers that can be created from numbers 12345 so that the numbers are not repeated and then numbers with repeated digits. Give the calculation.