# Grade - examples - page 171

If 5x + x² > 100, then x is not
2. Summands
Find two summands of the number 42, so that its product is minimized.
3. Square area
Complete the table and then draw each square. Provide exact lengths. Describe any problems you have. Side Length Area .
4. Bicycle gears
The toothed wheel on the bicycle pedal has 40 teeth, the wheel on the rear wheel has only 16 teeth. How many times does the rear wheel turn if the pedals rotate 50 times?
5. Warmer weather
This morning it was -6 °C. What temperature did the thermometer show yesterday if it was three times warmer?
6. Number unknown
Adela thought the two-digit number, she added it to its ten times and got 407. What number does she think?
7. Children
The group has 42 children. There are 4 more boys than girls. How many boys and girls are in the group?
The angle of a straight road is approximately 12 degrees. Determine the percentage of this road.
9. House numbering
The residential house has three entrances numbered even numbers, successive immediately behind. The sum of the two numbers on the outside entrances is 68. Calculate the middle of these three numbers.
10. Percents
How many percents is 900 greater than the number 750?
11. Percentages 5
\$5.25 is 7 1/2% of what number?
12. Digit sum
The digit sum of the two-digit number is nine. When we turn figures and multiply by the original two-digit number, we get the number 2430. What is the original two-digit number?
13. Surface area of the top
A cylinder is three times as high as it is wide. The length of the cylinder’s diagonal is 20 cm. Find the surface area of the top of the cylinder.
14. Inscribed sphere
How many percents of the cube volume takes the sphere inscribed into it?
Several pieces of bread were in the store. Half of them plus a half of bread bought a cookbook. Of the remaining bread, half of it plus half of the bread was bought by Mr. Novák. The last bread was bought by Ms. Small. How many breads were in the store at.
16. Two forces
The two forces F1 = 580N and F2 = 630N have the angle of 59 degrees. Calculate their resultant force F.
17. Windbreak
A tree at a height of 3 meters broke in the windbreak. Its peak fell 4.5 m from the tree. How tall was the tree?
18. Clouds
Approximately at what height is the cloud we see under an angle of 26°10' and see the Sun at an angle of 29°15' and the shade of the cloud is 92 meters away from us?
19. Ľé sweets
There are 20 sweets in the bag. Some are chocolate, other coconuts, and the remaining marzipan. Chocolate is 4 times more than coconut. Marzipan's less than chocolate. How much is in a bag of coconut sweets?
20. Water block
A block with a 50 cm2 base is filled with water 5 cm under the edge. How many can sugar cubes with 2 cm edge be thrown into a container that overflow water?

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