# Examples for 7th grade (seventh) - page 13

- The bridge

Across the circle lakepasses through its center bridge over the lake. At three different locations on the lake shore are three fishermen A, B, C. Which of fishermen see the bridge under the largest angle? - Box

Calculate the angle between box base 9 x 14 and body diagonal length 18. - Do you solve this?

Determine area S of rectangle and length of its sides if its perimeter is 102 cm. - Opposite numbers

Calculate opposite numbers (additive inverse) to given ones: - Workers

Workers digging a jump pit in the school yard. Pit has a cuboid shape with a length 12 m, a width 20 dm and depth 36 cm. They excavate 0.4 cubic meters of soil an hour. How much time (hours and minutes) is need to the excavate this pit? - Balance

The rod are 1.9 m long hanging weights 4 kg and 1 kg on ends. Where are centre of rod (distance from weight 4 kg) to be in balance? - Weight of air

What is the weight of air in the living room measuring width 5 m length 2 m and height 2.8 m? Air density is ρ = 1.2 kg/m^{3}. - Rectangle A2dim

Calculate the side of the rectangle, if you know that its area is of 2590 m^{2}and one side is 74 m. - Car

Car travels 1/3 of the trip on the first day, second day 2/5 of the trip and left even 340 km for next days. How long is the trip? - Potatoes

Potatoes contain 78.6% starch. How many potatoes need to obtain 27 kg of starch? - Map

Forest has an area of 36 ha. How much area is occupied by forest on the map at scale 1:500? - School books

At the beginning of the school year, the teacher gave out 480 books and 220 textbooks. How many students were in the class? - Paddlers

Students of canoeists trip traveled in three days 102 km. Second day traveled 15% more than first day and at the third day 9 km over the second day. How many kilometers traveled each day? - 3-bracket

May be the largest angle in the triangle less than 20°? - Count of roots

How many solutions has equation x. y = 7757 with two unknowns on the set of natural numbers? - Water container

Container with water weighs 1.48 kg. When we cast 75% of water container of water weight 0.73 kg. How heavy is an empty container? - Company

After increasing the number of employees by 15% company has 253 employees. How many employees take? - Intersections

How many intersections have circles with radius 16 mm and 15 mm, if the distance of their centers is 16 mm. - Two workers

Two workers together execute some work in 10 days. The first worker would have done himself in 20 days. How many days would have done himself a second worker? - Segments

Line segments 62 cm and 2.2 dm long we divide into equal parts which lengths in centimeters is expressed integer. How many ways can we divide?

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