# Latest problems - page 15

1. Flooring a room Find the cost of flooring a room 6.5 m by 5 m with square tiles of sides 25 cm at the rate of rupees 9.40 per tile.
2. The average The average of one set of 4 numbers is 35. The average of another set of number is 20. The average of the numbers in the two sets is 30. How many numbers are there in the other set?
3. Families 2 There are 729 families having 6 children each. The probability of a girl is 1/3 and the probability of a boy is 2/3. Find the the number of families having 2 girls and 4 boys.
4. Coal mine The monthly plan of 17,000 tons of coal exceeded the mine by 1/25. How many tonnes of coal have been harvested from the mine above plan?
5. Discount sale After the discount, the computer costs 9600, - CZK. How much did it cost when the price was reduced: a) by half b) by a third c) by one fifth and then by 160 CZK
6. Fractions 4 How many 2/3s are in 6?
7. A tile A tile setter is covering 5ft by 5ft square shower wall. Each tile covers 4 5/8in by 4 5/8in square. How many rows of tile are needed to reach 5ft? How many tiles are needed to cover 5ft by 5ft square
8. Three machines The power of the three machines is 2: 3: 5. Two most powerful machines produce 400 parts per hour. How many components make all three machines in 3 hours?
9. Cube The sum of all cube edges is 30cm. Find the surface area of the cube.
10. Helmet In nowadays cycling better results could be obtained not only due to rider physical preparation but also thanks to using updated technologies. One of the most important part of rider´s equipment is his or her helmet. While most bikers wear a helmet mainly
11. Temperature increase If the temperature at 9:am is 50 degrees. What is the temperature at 5:00pm if the temperature increases 4 degrees Fahrenheit each hour?
12. Tractors Wheel and belt tractors each day plow 8 ha of fields. For plow 76 hectares, the wheel would have to work for 12 days and 8 days with the belt tractor together. How many hectares do each day of each tractor?
13. Water current speed. Two cities along the river are 100 km apart. The powerboat downstream runs for 4 hours, upstream for 10 hours. Determines the river's current speed.
14. Chocolate I have a box of chocolate - white, milk and dark. The ratio of white to milk with dark is 3: 4. The ratio of white and milk to dark is 17: 4. Calculate what is the ratio between white, milk, dark chocolate.
15. Diagonals of a rhombus 2 One diagonal of a rhombus is greater than other by 4 cm . If the area of the rhombus is 96 cm2, find the side of the rhombus.
16. Pilot How high is the airplane's pilot to see 0.001 of Earth's surface?
17. Ages 2 A man's age is 4 times his son's age. After 5 years he will be just twice his son's age, find their ages.
18. The tub If we drop the 5 l from the first tap and the from second 2 liters of water, the water in the tub will have a temperature of 25°C. If we drop 3 l from the first tap and from second 4 l of water, the water in the tub will have a temperature of 21°C. Determi
19. Isosceles trapezoid The old father decided to change the top plate of an isosceles-like trapezoid with the basic dimensions of 120 cm and 60 cm, and the shoulder is 50 centimeters long. How much does it pay for a new plate and a square meter worth 17 euros?
20. Spruce height How tall was spruce that was cut at an altitude of 8m above the ground and the top landed at a distance of 15m from the heel of the tree?

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