Examples for 7th grade (seventh) - page 79

1. Soup from canteen For how many people is 90 liters of soup enough if we assume 3/8 liter of soup per person in the canteen?
2. Marriage sttus In our city, there are 3/5 of the women married to 2/3 of the men. Find what part of the population is free.
3. Bottle A company wants to produce a bottle whose capacity is 1.25 liters. Find the dimensions of a cylinder that will be required to produce this 1.25litres if the hight of the cylinder must be 5 times the radius.
4. Volcano The crater of a volcano is approximately in the shape of a cone of a base 3.1416 sq. Mi. The crater's depth is 1500 ft. How many cubic yards of earth would be required to fill this cavity?
5. Clothes Danka and Janka collect clothes. Danka had 9 more than Janka, so she gave her 7. Which now has more cloth and how many?
6. Pool tiles The pool is 25m long, 10m wide and 160cm deep. How many m2 of tiles will be needed on the walls and the pool? How many pieces of tile are needed when 1 tile has a square shape with a 20cm side? How much does it cost when 1m2 of tiles costs 258 Kc?
7. Three segments The circle is divided into 3 segments. Segment A occupies 1/4 of the area, segment B occupies 1/3 of the area. What part is occupied by section C? In what proportion are areas A: B: C?
8. The cube The cube has an edge of 25 cm. We cut it into small cubes of 5 cm long side. How many of these little ones left when we build a new cube of 20 cm in length?
9. Symbols If 2*3 = 60 ; 3*4 = 120 and 4*5 = 200, what is 2*5?
10. Simple equations Solve system of equations: 5x+3y=5 5x+7y=25
11. Circle simple Circumference of a circle is 6.28. What is the area of the circle?
12. Sewing Beth's mother can sew 235 pairs of short pants in 6 days while Lourdes can sew 187 pairs in 8 days. How many more pairs of short pants can Beth's mother sew?
13. The volume The volume of a solid cylinder is 260 cm3 the cylinder is melt down into a cuboid, whose base is a square of 5cm, calculate the height of the cuboid and the surface area of the cuboid
14. Perimeter of square The square has a circumference 17cm. What is its area?
15. One hectare How many square meters are one hectare?
16. Cube walls Find the volume and the surface area of the cube if the area of one of its walls is 40 cm2.
17. Velocipedes In the 19th century, bicycles did not have a chain drive, and the pedals were connected directly to the wheel axis. This wheel diameter gradually increased until the so-called high bicycles (velocipedes) with a front wheel diameter of up to 1.5 meters, whi
18. The number The number of 1 cm cubes required to make 4 cm cube is?
19. Water flow 2 How many litres of water will flow in 7 minutes from a cylindrical pipe 1 cm in diameter, if the water flows at a speed of 30 km per hour
20. Metal rails Dad needs to improve the edges of the wooden boxes - to be reinforced with metal rails. How many cms of rails will he need if the box has the shape of a prism with the length of the edges 70cm 70cm and 120cm?

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