Examples for 7th grade (seventh) - page 11
- Rotating cone II
Calculate area of surface of rotating cone with base radius r=19 cm and height h=9 cm.
At the glass shop we have to cut 8 sheets of glass. Each was shaped a square with sides of 18 cm. We paid 44 CZK. How much is a 1 m2 of glass?
Cyclist who rides at an average speed 16 km/h travels trip distance 10 min before the cyclist who rides at an average speed 11 km/h. What is the length of this cyclist trip(distance in km)?
Calculate the length of the arm r of isosceles triangle ABC, with base |AB| = 18 cm and a height v=17 cm.
- Magnification of the square
If we increase the square side, increase the content of the 80 %. About what percentage was increased his sides?
- 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.
An oil tanker can be emptied by the first pump in 4.9 hours. Second pump can empty an tanker in 8 hours. If the first pump started at 4:00 and second 1.4 hour later, at what time will the tanker be empty?
- 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
From 6 products are 3 scrap. What is the probability that the random pick of 2 products have no defective product?
- 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.
- Water inlets
Inlet valve with a flow rate of 12 liters per second is filled tank for 72 minutes. How long take to fill full tank if we open one more such valve half an hour after?
- 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.
- 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
- Triangle angles
The angles α, β, γ in triangle ABC are in the ratio 6:2:6. Calculate size of angles.