# Examples for 7th grade (seventh)

1. Prism
Find the volume and surface area of prism with base of an equilateral triangle with side 7 dm long and the body height of 1.5 m.
2. Wood cuboid
What is the weight of the wood cuboid 15 cm, 20 cm, 3 m if 1 m3 wood weighs 800 kg?
3. Freezer
The freezer has the shape of a cuboid with internal dimensions of 12 cm, 10 cm, 30 cm. A layer of ice of 23 mm thick was formed on the inner walls (and on the opening) of the freezer. How many liters of water will drain if we dispose the freezer?
4. Prism - eq triangle
Calculate the volume and surface of the prism with the base of an equilateral triangle with side a = 4cm and the body height is 6cm.
5. Cents no more
Janko bought pencils for 35 cents each. Neither he nor the salesperson had small coins just a whole € 1 coin. At least how many pencils had to buy to pay for the whole euros?
6. The cube
The surface of the cube is 150 square centimeters. Calculate: a- the content of its walls b - the length of its edges
7. The wall
We have to build a cuboid wall with dimensions base 30 cm and 45 cm and height 3.25 meters. Calculate how many we need bricks if we spend 400 pieces of bricks to 1 m3 of wall?
8. Tractors
Six tractors plowing the field for 8 days. After two days, two tractors broke down. How many days were prolonged work in the field?
9. Land area
A land area of Asia and Africa are in a 3: 2 ratio, the European and African are is 1:3. What are the proportions of Asia, Africa, and Europe?
10. Mother and daughter
The ratio of years mother and daughter is 5:2. After 7 years the ratio is 2: 1. How many years ago daughter was born?
11. Wallet
From the money that was in my Maria wallet she spent a fifth on the first purchase. From remain money she could buy 2 kg of strawberries. But she bought only 1.5 kg for 60 Kc. How much money was Marie originally in her wallet?
12. Water inlets
Inlet valve with a flow rate of 12 liters per second is filled tank for 72 minutes. How long take to fill full tank if we open one more such valve half an hour after?
13. Millionaire
Mr. Smith have gone withdraw from bank saving interest € 1,500. How big was his initial deposit if the annual interest rate is 1.5%?
14. Math heart
Stylized heart shape created from a square with side 5 cm and two semicircles over his sides. Calculate the content area and its circumference.
15. Unknown number
Identify unknown number which 1/5 is 40 greater than one tenth of that number.
16. Circle r,D
Calculate the diameter and radius of the circle if it has length 52.45 cm.
17. Assistant
Assistant rewrote 15% of the entire manuscript in 12 hours. How many hours must still write to rewrite the rest of the manuscript?
18. Profitability
The purchase price of goods is 13000, the sales price is the 20000. What is the profitability as a percentage?
19. Division of money
Calculate how many euros have Matthew, Miriam, Lucy, Michael, Janka when together have 2,700 euros and the amounts are at a ratio of 1:5:6:7:8.
20. After 16 years
After 16 years will Dana be five times older as she was four years ago. After how many years will Dana celebrate her 16th birthday?

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