Examples for 7th grade (seventh)
Number of examples found: 1974
- Concrete hatch
The concrete hatch for a round well has a diameter of 1300 mm and a thickness of 80 mm. Determine its weight in kg if the density of the concrete is 2545 kg/m3
- The water tank
The water tank has the shape of a sphere with a radius of 2 m. How many liters of water will fit in the tank? How many kilograms of paint do we need to paint the tank, if we paint with 1 kg of paint 10 m2?
- Outside tangents
Calculate the length of the line segment S1S2 if the circles k1 (S1, 8cm) and k2 (S2,4cm) touch the outside.
- The pot
The pot is a cylinder with a volume of V = 7l and an inner diameter of d = 20cm. Find its depth.
- On Sunday
On Sunday the temperature reached a high of 38° above 0. That night it dropped to 23° below 0. What is the difference between the high and low temperatures for Sunday?
The cube-shaped cube box has the dimensions of 30 cm × 30 cm × 12 cm. How many CZK (Czech crowns) would cost be the biggest cake that would fit into the box when a 10 cm³ cake costs CZK 0.5? The cake has the same shape as the box.
- Isosceles - isosceles
It is given a triangle ABC with sides /AB/ = 3 cm /BC/ = 10 cm, and the angle ABC = 120°. Draw all points X such that true that BCX triangle is an isosceles and triangle ABX is isosceles with the base AB.
Cheetah elapse 150 m for 5 seconds, the eagle reaches speeds up to 230 km/h, dolphin swims 1.2 km per minute. Which animal is the fastest and slowest? The results write as meters per second (m/s).
- Wood cuboid
What is the weight of the wood cuboid 15 cm, 20 cm, 3 m if 1 m3 wood weighs 800 kg?
- Two trains
Two trains go at each other. First at speed 40 km/h and the second at speed 60 km/h. At what distance will be 30 minutes before they will meet?
- Class 8.A
Three quarters of class 8.A went skiing. Of those who remained at home one third was ill and the remaining six were on math olympic. How many students have class 8.A?
Jan is 13 years and Peter 21 years old. For how many years will their ages in the ratio of 7:9?
The base of the prism is a rhombus with a side 30 cm and height 27 cm. The height of the prism is 180% longer than the side length of the rhombus. Calculate the volume of the prism.
- Without 2
Without multipying, tell whether the product 0.644 x 0.25 will be greater than 1 or less than 1? Explane how you know. Then find the product.
- Two angles
The triangles ABC and A'B'C 'are similar. In the ABC triangle, the two angles are 25° and 65°. Explain why in the triangle A'B'C 'is the sum of two angles of 90 degrees.
- Sheet of paper
Is the sheet of paper measuring 18 and 25 cm enough for taping 9 cm cubes with an edge? (1 = yes, 0 = no)
Seamstress bought two kinds of textile together 25 meters. One at 50 SKK and the second 70 SKK per meter. How many meter bought from this two textiles when paid totally 1540 SKK?
- Rectangle - sides 3
If in the rectangle ABCD we enlarge the side a by 5 cm and decrease the side b by 2 cm, the rectangle area will be reduced by 5 cm². When we decrease the length of the side a by 4 cm and and at the same time we increase the length of side b by 3 cm we inc
- Copper sheet
The copper plate has a length of 1 m, width 94 cm and weighs 9 kg. What is the plate thickness, if 1 m3 weighs 8715 kg?
- Empty barrel
In the backyard is an empty barrel with a volume of 2 hl. How many liters are missing at the edge, when 53 liters flowed into it for 1 day and 68 liters of water for 2 days?