Examples for 7th grade (seventh) - page 12
- Sea on the Moon
Assume that the Moon has sea, the same composition as on the Earth (has same density of salt water). Calculate dive of boat floating in the sea on the Moon, when on Earth has dive 3.6 m. Consider that the Moon has 6.5-times smaller gravitational accelerati
- Dog II
Journey from a rangers' home to the town is 6 km. Mr. ranger started from his home and went 3 km per hour. His women came from the town and also went 3 km per hour. With ranger started dog and runs in 12 km in 1 hour. The dog went to ranger's women then.
- Election mathematics
In elections, 14 political parties received this shares of voters: party A 49.8 %party B 11.4 %party C 7.9 %party D 6.3 %party E 6.1 %party F 5.7 %party G 4.6 %party H 2.9 %party I 2.2 %party J 1.3 %party K 1 %party L 0.7 %party M 0.1 % Calculate what th
- Cone and the ratio
Rotational cone has a height 23 cm and the ratio of the base surface to lateral surface is 7: 9. Calculate a surface of the base and the lateral surface.
- EQL triangle
Calculate inradius and circumradius of equilateral triangle with side a=77 cm.
The perimeter of a circular sector with an angle 1.8 rad is 64 cm. Determine the radius of the circle from which the sector comes.
- Cube wall
Surface of first cube wall his 225 mm2. Second cube area is 60% of the surface of the first cube. Determine the length of the edge of the second cube (x).
Truck went for 4 hours and 48 minutes. If truck increase speed by 21 km/h, went same distance in 1.8 hours. Calculate this distance.
- Equilateral triangle
Calculate the side of an equilateral triangle, if its area is 892 mm2.
- Milk package
Milk is sold in a box with dimensions of 9.5 cm; 16.5 cm and 6.5 cm. Determine the maximum amount of milk that can fit into a box. Coating thickness is negligible.
- Triangle angles
The angles α, β, γ in triangle ABC are in the ratio 6:2:6. Calculate size of angles.
Mailbox is opening at regular intervals 3 times a day. The first time is opened at 8:00 and the last at 19:00. Calculate hours when mailbox is opened during day.
- Ultra expensive ramps
The village Čakajovce have two level railway crossings (the ramps), the railway company ZSR decided to replace it. The price for upgrading the two crossings is 302065 Euros. Calculate how many houses for 77000 euros is possible to obtain at this price. Ca
- Three workers
Three workers A, B, C have to work on a specific task. Workers A and B completed whole task in 11 days, B together with C for 15 days, A together with C for 24 days. How long it would take to complete the task every one of them alone? How long it would.
Between the two ports on the river is going steamship. The journey there and back takes 8:42. Downstream steamship traveling at 20 km/h, upstream 9 km/h. What is the distance between the ports?
- XY triangle
Determine area of triangle given by line 7x+8y-69=0 and coordinate axes x and y.
Marie earns 3 liters of blueberries for 3.4 hours, Peter 2.4 liters for 2.9 hours. How long have earns together one liter?
Calculate how many 25 kg bags of leveling concrete must be purchased if we leveling room 15 m2 to the "height" 6 mm if consumtion is 1.5 kg per square meter and millimeter thickness.
- Christmas Day
In leap years was 53 Sundays. On what day of the week fell to Christmas Day?
Calculate the area and perimeter of a parallelogram whose two sides are long a=24 cm b=22 cm and height ha = 6 cm long.