# Examples for 7th grade (seventh) - page 42

1. Copiers
Three copiers will do the same in an hour k copies. How many copies would be done in an hour by four such copiers? ?
2. Similarity
ABC is a triangle wherein a = 4 cm, b = 6 cm, c = 8 cm. Is it similar to the triangle DEF: d = 3 cm, e = 4.5 cm, f = 6 cm? If so, determine the ratio of similarity.
3. The deposit
Deposit has been placed for one year at an annual rate of 4.5%. After the added interst amount rose to € 2,612.5. Determine initial deposit.
4. On the farm
On the farm were housed 70 heads of cattle with food supply for 180 days. After 60 days, 10 head of cattle sold, and for the next 30 days they sold 10 more. How many days is sufficient supply of feed for the remaining cattle?
5. Gardens colony
Gardens colony with dimensions of 180 m and 300 m are to be completely divided into the same large squares of the highest area. Calculate how many such squares can be obtained and determine the length of the square side.
6. Classroom
In a class are 32 pupils. Boys are 8 less than girls. How many boys and girls are in the classroom?
7. 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%?
8. Calcium and citality
The daily dose of calcium obtained using 0.75 liters of milk and 60 grams of cheese. A/ At the morning I drank half a liter of milk. How much cheese I must eatto eat a daily dose of calcium? b / I ate 50 grams of cheese, how much milk I must drink? c /.
9. Potatoes
When planting potatoes there are consumed 230 kg of seed per 1 ha. Calculate the weight of the seed needed for fitting a square area with a side length 325 meters.
10. Land
Land has a rectangular shape, its surface area is 1.45 hectares. Its width is 250 m. Determine the length of the land.
11. Surface area of cylinder
Determine the lateral surface of the rotary cylinder which is circumscribed cube with edge length 5 cm.
12. Sugar
Sugar factory produced 127 tons of sugar in 1 day at 14% sugar content . How many tons of pure beet sugar factory processed in 1 day?
13. Outer angles
The outer angle of the triangle ABC at the A vertex is 71°40 ' outer angle at the vertx B is 136°50'. What size has the inner triangle angle at the vertex C?
14. Lesson exercising
The lesson of physical education, pupils are first divided into three groups so that each has the same number. The they redistributed, but into six groups. And again, it was the same number of children in each group. Finally they divided into nine equal gr
15. Salt
1 t of sea water contains 25 kg of salt. How many tons of seawater must be evaporated to obtain 2 q of salt?
16. Translations
If I going to translate the book 6 pages per day I translate it 4 days earlier than if I translated 5 pages a day. If I translate 4 pages a day I translate it for how many days.....?
17. Painters
15 painters painted fence for 280 minutes. For how many minutes paint half of this fence 12 painters?
18. Well
Rope with a bucket is fixed on the shaft with the wheel. The shaft has a diameter 50 cm. How many meters will drop bucket when the wheels turn 15 times?
19. Rabbit family
Rabbit family ate 32 pieces of carrots, small one ate 6 pieces, dad 5 more than the mother. How much ate mom?
20. Percentage reduction
Reducing the unknown number by 19% get number 700.7 Determine unknown number.

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