# Examples for 8th grade - page 63

- Right triangle

It is given a right triangle angle alpha of 90 degrees beta angle of 55 degrees c = 10 cm use Pythagorean theorem to calculate sides a and b - Roses

On the large rosary was a third white, half red, yellow quarter and six pink. How many roses was in the rosary? - Concrete block

Determine the volume of concrete block whose one edge of the base has a length 3 meters, body diagonal is 13 meters and its height is 12 meters. - Farm2

The farm bred turkeys, geese, hens and chickens. Everything is 400. Turkeys and geese a hen are 150. No hen has more than one chicken, but some hens has no chick. Half of them is also a quarter of the chickens. When the turkey subtracting 15, we get 75. Ho - New refrigerator

New refrigerator sells for 1024 USD, Monday will be 25% discount. How much USD will save, and what will be the price? - Runners circle

Pepa circles the track in 36 seconds. Kamil in 42 seconds. They started together. How many seconds will meet again at the start? - Three numbers

Find three numbers so that the second number is 4 times greater than the first and the third is lower by 5 than the second number. Their sum is 67. - Inscribed circle

XYZ is right triangle with right angle at the vertex X that has inscribed circle with a radius 5 cm. Determine area of the triangle XYZ if XZ = 14 cm. - Two rooms

Woman cleans the room in 30 minutes a man in 90 minutes. How long will take they clean two rooms? - Coal

If the daily consumption of 1.6 tons of coal, it is sufficient to supply the boiler for 42 days. How long is sufficient to supply when will burn only 1.2 tons of coal a day ? - Mother and daughter

The ratio of years mother and daughter is 5:2. After 7 years the ratio is 2: 1. How many years ago daughter was born? - Painters

Five painters painting the fence for eight days. How many days over will take work if paint the fence only four decorators? - Scale of the map

Determine the scale of the map if the actual distance between A and B is 720 km and distance on the map is 20 cm. - 7 roses

Peter buys 7 roses. When he pay for it left him 4 euro. If he bought 5 roses left him 40 euros. How many euros had Peter before buying? - Rhumbline

Find circumference and area of the rhumbline ABCD if the short side AD of which has a length of 5 cm, and the heel of the height from D leading to the AB side divides the AB side into two sections of 3 cm and 4 cm. - Prism

Find the volume and surface area of prism with base of an equilateral triangle with side 7 dm long and the body height of 1.5 m. - Gearing

Gearing consists of two wheels, one is 88 and second 56 teeth. How many times turns smaller wheel to fit the same teeth as in the beginning? How many times will turn biggest wheel? - 4 pipes

The tank flows out by 4 pipes in 6 hours 120 hl water. How much water flows out of 5 pipes of the same diameter in 14 hours? - Pyramid 4sides

Calculate the volume and the surface of a regular quadrangular pyramid when the edge of the base is 4 cm long and the height of the pyramid is 7 cm. - Solutions

How much 60% solution and how much 35% solution is needed to create 100 l of 40% solution?

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