# Examples for 7th grade (seventh) - page 11

1. 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.
2. 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.
3. Triangle angles
The angles α, β, γ in triangle ABC are in the ratio 6:2:6. Calculate size of angles.
4. EQL triangle
Calculate inradius and circumradius of equilateral triangle with side a=77 cm.
5. Sector
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.
6. 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).
7. Truck
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.
8. Equilateral triangle
Calculate the side of an equilateral triangle, if its area is 892 mm2.
9. Mailbox
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.
10. Parallelogram
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.
11. XY triangle
Determine area of triangle given by line 7x+8y-69=0 and coordinate axes x and y.
12. Three workers
Three workers A, B, C have to work on a specific task. Workers A and B completed whole task in 14 days, B together with C for 23 days, A together with C for 13 days. How long it would take to complete the task every one of them alone? How long it would.
13. Tractors
Six tractors plowing the field for 8 days. After two days, two tractors broke down. How many days were prolonged work in the field?
14. Steamship
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?
15. Blueberries
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?
16. 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
17. Coin and die
Flip a coin and then roll a six-sided die. How many possible combinations are there?
18. Christmas Day
In leap years was 53 Sundays. On what day of the week fell to Christmas Day?
19. Fuel consumption
Citroen car has an average gasoline consumption of 5.3 liters per 100 kilometers. What is the car range for a full tank of volume 68 liters?
20. Leveling
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.

Do you have an interesting mathematical example that you can't solve it? Enter it, and we can try to solve it.

To this e-mail address, we will reply solution; solved examples are also published here. Please enter e-mail correctly and check whether you don't have a full mailbox.