# Examples for 8th grade - page 30

- Triangle TBC

TBC is isosceles triangle with base TB with base angle 52° and legs length |TC| = |BC| = 30. How long is the base TB? - Sea water

One tonne of sea water contains 25 kg of salt. How many tonnes of sea water need to be evaporated to obtain 1 tonne of salt? - Workers

Group of workers washing half of the windows of the building in two hours. How long will take half the workers wash all the windows of the building? - Cacao

Cacao contains 34% filling. How many grams of filling are in 130 g cacao. - Trrops - soldiers

Food stocks will last 20 soldiers of the 4-day training. How many days they could extend training if four soldiers become sick? - Polygon 42

Which polygon has 42 more diagonals than sides? - Liters od milk

The cylinder-shaped container contains 80 liters of milk. Milk level is 45 cm. How much milk will in the container, if level raise to height 72 cm? - Wood

Wood contains 12% water. 1 m^{3}of wood weighs 650 kg. How many liters of water it contains? - Container

First day got off 1/4 water from full container, second day 1/5 of the remaining water. How many percent remain container filled? - Three workers

Three workers were rewarded CZK 7200 and the money divided by the work they have done. First worker to get twice than the second, the second three times more than the third. How much money each worker received? - Mother and daughter

Three years ago mother was three times older than daughter. After nine years she will be only twice old. How old is mother (and daughter)? - Barbara

Barborka goes to school with backpack that was 3 - times more expensive than a bag slipper. If backpack was 33 euros cheaper it was cost same as bag slipper. How many cost backpack and how many bas slipper? - Percentages

Expressed as a percentage: - Bakery

How heavy must prepare bread at a bakery if lose during baking 14% of water and after baking must have 1.6 kg? (Calculate to the nearest gram) - Cuboid

The cuboid has a surface area 8710 cm^{2,}the length of its edges are in the ratio 3:2:1. Calculate the volume of the cuboid. - Steps

How many steps you save if you go square estate for diagonal (crosswise), rather than circumvent on the two sides of its perimeter with 298 steps. - Kitchen

Kitchen roller has a diameter 85 mm and width of 337 mm. How many square millimeters roll on one turn? - Barrel with liquid

Barrel with grain weight 263 kg. When it shed 43% of grain, ha weight 170 kg. What is the weight of empty barrel? - Circle arc

Circle segment has a circumference of 13.26 mm and 252.03 mm^{2}area. Calculate the radius of the circle and size of central angle. - Rectangle

Area of rectangle is 1430. Its length is 29 larger than the width. What are the dimensions of the rectangle?

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