1. The surface area How much percent will the surface area of a 4x5x8 cm block increase if the length of the shortest edge is increased by 2 cm?
2. Cuboid and ratio Find the dimensions of a cuboid having a volume of 810 cm3 if the lengths of its edges coming from the same vertex are in ratio 2: 3: 5
3. Squares ratio The first square has a side length of a = 6 cm. The second square has a circumference of 6 dm. Calculate the proportions of the perimeters and the proportions of the contents of these squares? (Write the ratio in the basic form). (Perimeter = 4 * a, conte
4. Five-gon Calculate the side a, the circumference and the area of the regular 5-angle if Rop = 6cm.
5. Fall sum or same Find the probability that if you roll two dice, it will fall the sum of 10, or the same number will fall on both dice.
6. Annulus Two concentric circles with radii 1 and 9 surround the annular circle. This ring is inscribed with n circles that do not overlap. Determine the highest possible value of n.
7. Tourist cottage The tourist cottage has 11 rooms for 16 guests, some of them are doubles, some singles. How many are double rooms and how many are single rooms?
8. Two gardens The total area of the two gardens is 864 m2. The first garden is 60 m2 smaller than three times the second garden. What is the area of each garden?
9. Twelve ties The price of 12 ties before the discount was the same as 15 ties after discount. Calculate the price of 1 tie after discount, if you know that the discount price of one tie fell by 40 CZK?
10. Corona virus Calculate an estimate of the percentage of GDP (Gross Domestic Product) declined due to the quarantine related to the corona COVID-19 virus that lasts for 2 months, during which time the economic activity is down by 80%.
11. Wall thickness The hollow metal ball has an outside diameter of 40 cm. Determine the wall thickness if the weight is 25 kg and the metal density is 8.45 g/cm3.
12. What percentage What percentage of the Earth’s surface is seen by an astronaut from a height of h = 350 km. Take the Earth as a sphere with the radius R = 6370 km
13. What percent What percent of 51 3/5 is 47 2/5?
14. Self-oscillation period The water in the vessel carried by the boy has a self-oscillation period of 0.8 s. What is the size of the boy's movement speed when the length of the boy's step is 60 cm? Give the result in m/s.
15. Discounts 2 The local fitness center offers membership discounts for hospital employees. According to the membership brochure, you will receive a discount of 25% on a membership that normally costs \$65 per month. How much will you pay for an annual membership if you
16. Runners If John has a running speed of 3.5miles per hour and Lucy has a speed of 5 miles per hour. If John starts running at 10:00 am and Lucy starts running at 10:30 am, at what time will they meet? (as soon as possible)
17. Birth Let's assume that the probability of the birth of a boy and a girl in the family is the same. What is the probability that in a family with five children, the youngest and oldest child is a boy? Divide number 135 into two additions so that one adds 30 more than 2/5 of the other add. Write the bigger one. Every year, at the same time, an increase in the volume of wood in the forest is measured. The increase is regularly p% compared to the previous year. If in 10 years the volume of wood has increased by 10%, what is the number p? From point A, the power line pole is seen at an angle of 18 degrees. From point B to which we get when going from point A 30m away from the column at an angle of 10 degrees. Find the height of the power pole.