Combinatorics - math word problems
- Possible combinations - word
How many ways can the letters F, A, I, R be arranged?
- Pairs of socks
Ferdinand has twelve pairs of socks, one sock is leaky. What is the probability of putting on a leaky sock?
How many three-digit natural numbers are divisible by 25?
During auto-tuning, the TV searched for 25 channels, four of which were music. The channels are stored in the TV's memory in random order. Express the percentage of the event that the music channel will be saved first.
How many ways can we thread 4 red, 5 blue, and 6 yellow beads onto a thread?
- Cube construction
A 2×2×2 cube is to be constructed using 4 white and 4 black unit cube. How many different cubes can be constructed in this way? ( Two cubes are not different if one can be obtained by rotating the other. )
- Ball bearings
One bearing is selected from the shipment of ball bearings. It is known from previous deliveries that the inner bearing radius can be considered as a normal distribution of N (µ = 0.400, σ2 = 25.10^−6). Calculate the probability that the selected radius w
- Boys and girls
There are 20 boys and 10 girls in the class. How many different dance pairs can we make of them?
- Year 2020
The four-digit number divided by 2020 gives a result of 1, **. (Can not be in form 1,*0. ) Write all the options.
- Two groups
The group of 10 girls should be divided into two groups with at least 4 girls in each group. How many ways can this be done?
From the bag with numbered balls (numbers 1,2,3,. ..20) we pick one ball. What is the probability of choosing a number containing 1?
- Graduation party
There are 15 boys and 12 girls at the graduation party. Determine how many four couples can be selected.
Records indicate 90% error-free. If 8 records are randomly selected, what is the probability that at least 2 records have no errors?
- Genetic disease
One genetic disease was tested positive in both parents of one family. It has been known that any child in this family has a 25% risk of inheriting the disease. A family has 3 children. What is the probability of this family having one child who inherited
- Dice and coin
A number cube is rolled and a coin is tossed. The number cube and the coin are fair. What is the probability that the number rolled is greater than 2 and the coin toss is head?
- Probability of malaria
A survey carried out at a certain hospital indicates that the probability that a patient tested positive for malaria is 0.6. What is the probability that two patients selected at random (i) one is negative while the other tested positive? (i) both patie
- Today in school
There are 9 girls and 11 boys in the class today. What is the probability that Suzan will go to the board today?
- One three
We throw two dice. What is the probability that max one three falls?
- Holidays with grandmam
We have packed three T-shirts - white, red, orange and five pants - blue, green, black, pink and yellow. How many days can we spend with the old mother if we put on a different combination of clothes every day?
95% of the components manufactured on the lathe comply with the standard, of which 80% of the components are first-class. How likely can we expect a manufactured part to be first class?
Would you like to compute count of combinations?