# Examples for 7th grade (seventh) - page 67

1. King's birthday
To celebrate the king's birthday workers fire 1/5 all purchased rockets. To celebrate the Queen's birthday fire 1/6 of the remaining rockets and to celebrate the birthday of king's son remaining 15,000 rockets. How many rockets they purchased?
2. Hexagon area
The center of the regular hexagon is 21 cm away from its side. Calculate the hexagon side and its area.
3. Driver
I drive at an average speed of 70km/h, I drive 10 thousand km. How long did it take me?
4. Cancer
Of the 80 people 50 people ill cancer. What percentage of people isn't ill?
5. Shots
Determine the percentage rate of keeper interventions if from 32 shots doesn't caught four shots.
6. Parallelogram
Calculate the missing side of a parallelogram, if you know the perimeter o and one side: a) o = 7.2 cm; b = 1.8 cm b) o = 5.4 cm; a = 1.9 cm
7. Coolant
The driver of the car cooler filled with a mixture of 3.9 liters and 2.6 liters of water antifreeze coolant. At what rate are this two components of the mixture?
8. Diameter
The diameter of a circular plot is 14 dm. Find the circumference and area.
9. Parallelogram perimeter
The ABC triangle with sides a = 5cm, b = 3cm, c = 40mm has the center of the sides of the K,L,M. How many cm have the KBLM parallelogram perimeter?
10. Bicycle wheel
After driving 157 m bicycle wheel rotates 100 times. What is the radius of the wheel in cm?
11. The cellar
Mr Novák has a cellar and a cellar window in the chalet has 0.6 meter square window. The window wishes to place an X-shaped grid in a square. He uses iron welded bars. Calculate the lengths of individual bars and what the total length of the bars he has t
12. Rectangle 39
Find the perimeter and area of the rectangular with vertices (-1, 4), (0,4), (0, -1), and (-4, 4)
13. Percents - easy
How many percent is 432 out of 434?
14. Volume and area
What is the volume of a cube which has area of 361 cm2?
15. Proportion
write the following proportion 8 is to 64 as to 2 is to x
16. Seagull
Artificially created island in the shape of a circle with a radius of 50 m is overgrown with grass. The only exception is a landing area for helicopters in the shape of a rectangle measuring 15 m and 8 m. What is the probability that the flying seagull (wi
17. Boys and girls
There are 28 girls in the hall. 5/7 of all children are boys. How many children and how many boys are there?
18. Broken tree
The tree is broken at 4 meters above the ground and the top of the tree touches the ground at a distance of 5 from the trunk. Calculate the original height of the tree.
19. Study
For 7 hours study, she scored a 75 so if she made 93 how many hours would she need to study?
20. Circle chord
Calculate the length of the chord of the circle with radius r = 10 cm, length of which is equal to the distance from the center of the circle.

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