# Examples for 8th grade - page 17

- Isosceles trapezoid

Calculate the area of an isosceles trapezoid whose bases are in the ratio of 4:3; leg b = 13 cm and height = 12 cm. - The camp

At the end of the camp a 9 friends exchanged addresses. Any friend gave remaining 8 friends his card. How many addresses they exchanged? - Goods

To the market is introducing a new product, the first week is sold at a reduced price. 5 products is sell at an entry price same as 3 products at the normal price. How much % is reduced price less than the current price for this product? - Diagonals of the rhombus

Calculate height of rhombus whose diagonals are 15 cm and 5 cm. - 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. - Five-digit

Find all five-digit numbers that can be created from numbers 12345 so that the numbers are not repeated and then numbers with repeated digits. Give the calculation. - Perimeter and legs

Determine the perimeter of a right triangle if the length of one leg is 75% length of the second leg and its content area is 24 cm^{2.} - The percentages in practice

If every tenth apple on the tree is rotten it can be expressed by percentages: 10% of the apples on the tree is rotten. Tell percent using the following information: a. in June rained 6 days b, increase worker pay 500 euros to 50 euros c, grabbed 21 fro - Radians compare

What is greater angle? 1 radians or 1π radians? - Hexagon A

Calculate area of regular hexagon inscribed in circle with radius r=7 m. - Cylinder

The cylinder surface is 139 dm^{2,}its height is equal to the radius of the base. Calculate height of this cylinder. - Perpendicular

Determine the slope of the line perpendicular to the line p: y = 9x +7. - n-gon

Gabo draw n-gon, which angles are consecutive members of an arithmetic sequence. The smallest angle is 70° biggest 170°. How many sides have Gabo's n-gon? - Sea water

Mixing 68 kg of sea water with 73 kg rainwater is created water containing 3% salt. How many percent sea water contains salt? - Powers

Express the expression ? as the n-th power of the base 7. - Tanks

Fire tank has cuboid shape with a rectangular floor measuring 11 m × 14.3 m. Water depth is 1.3 m. Water was pumped from the tank into barrels with a capacity of 3.9 hl. How many barrels were used, if the water level in the tank fallen 3 cm? Wri - Trains

On double track line between stations K and M went against each other two trains. The first train passed the distance between stations for 2 hours, the second, which had an average speed of 15 km/h more passed for 1.55 hours. Calculate the distance betwee - Tmp workers

Three temporary workers cleaned 60 m of walkway in 5 hours. How many meters of the walkway cleared seven volunteers for eight hours? - 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? - Beer permille

In the 5 kg of blood of adult human after three 10° beers consumed shortly after another is 6.6 g of the alcohol. How much is it as per mille?

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