# Reason - high school - math problems

#### Number of problems found: 342

• Balls in row Calculate the number of ways of placing 4 black balls, 4 turquoise balls and 5 gold balls in a row.
• Apple collecting Luke, Peter and Tibor compared how many kilograms of apples they had collected. They found that the arithmetic mean of what Luke and Peter collected was 10 kg larger than Tibor's contribution, and the arithmetic mean of what Luke and Tibor collected was 3
• Error rate The exam has 6 questions. Students have an error rate of 20% and can have a maximum of 1 question wrong. What is the probability that they will succeed?
• In the In the arithmetic sequence a1 = 4.8, d = 0.4. How many consecutive members, starting with the first, need to be added so that the sum is greater than 170?
• Two numbers One number is by 79 larger than the other. If we divide the larger number by the smaller one, we get the ratio 5 and the remainder 11. Determine both numbers.
• The vaccination The vaccination coverage of the population is 80%. Unvaccinated make up 60% of all infected. What percentage are unvaccinated more likely to be infected?
• The three The three boys Adam, Boris and Cyril are to be taken on a two-seater ski lift. How many different removal options are there? What would it be like if four boys or five were to be taken away?
• Wheel gear A drive wheel of radius 2 is connected to a drive wheel of radius 1 by a pulley of length 17. What is the distance between the wheel axles?
• Chi square A manufacturer of phone batteries claims that his batteries' lives are approximately normally distributed with a standard deviation equal to 0.9 years. If a random sample of 10 of these batteries has a standard deviation of 1.2 years. Do you think that th
• Poisson distribution - daisies The meadow behind FLD was divided into 100 equally large parts. Subsequently, it was found that there were no daisies in ten of these parts. Estimate the total number of daisies in the meadow. Assume that daisies are randomly distributed in the meadow.
• Two workers One worker makes a part 4 hours and the second 9 hours later than they would make the same part together. How long does it take for each worker to make the part himself?
• Hockey Championships At the 2021 World Hockey Championships, there are eight teams in Group A, each of which plays seven matches. There are 4 points for each team to gain points (3-2-1-0), but it is always paired with the opponent's points ( 0-1-2-3). How many points are ther
• A married A married couple planned to have 3 children. i. List the possible combinations of the sexes of 3 children. Use B for boy and G for girl. ii. Calculate the probability that all three children would be of the same gender
• Three wagons I have 6 different people (A, B, C, D, E, F), which I have to place into 3 wagons, if it depends on who will board. How many options are there?
• A bag A bag contains 9 blue marbles and 1 green marble. What is the probability of drawing a blue marble followed by a green marble, without replacing the first marble before drawing the second marble.
• Seeds From a box of spruce seeds with the germination of 80%, we randomly select 10 seeds and plant them. Find the median of the random variable: the number of germinating seeds.
• Metal balls Four metal balls with a diameter of 5 cm are placed in a measuring cylinder with an inner diameter of 10 cm. What is the smallest water volume to be poured into the cylinder so that all balls are below the water level?
• Two boys Two boys weighing 60kg and 90kg move on roller skates and are attracted to each other by a rope. One boy exerts a force of 15N. What force does the other boy exert? What accelerations will the boys gain? Do not consider friction or air resistance.
• Harry Harry Thomson bought a large land in the shape of a rectangle with a circumference of 90 meters. He divided it into three rectangular plots. The shorter side has all three plots of equal length, their longer sides are three consecutive natural numbers. Fi
• Three-digit numbers How many three-digit numbers are not closer to 600 on the number axis than to 400?

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Reason - math problems. Examples for secondary school students.