# Examples for 8th grade - page 62

- Percent chaining

Calculate 20% from 70% from 80 km - Pupils at cinema

Alena bought movie tickets for two groups of pupils. The first group purchased 7 tickets for 1st and 5 tickets for 2nd place and she pay 62Kč. For the second group bought 11 tickets for 1st and 4 tickets for 2nd place and pay 82Kč. How much was the ticket - The chord

Calculate a chord length which the distance from the center of the circle (S, 6 cm) equals 3 cm. - Tripled square

If you tripled the length of the sides of the square ABCD you increases its content by 200 cm^{2.}How long is the side of the square ABCD? - Chord 2

Point A has distance 13 cm from the center of the circle with radius r = 5 cm. Calculate the length of the chord connecting the points T1 and T2 of contact of tangents led from point A to the circle. - Force meter

We put the statuette on the force meter. The force meter showed a value 25 N. Then we placed the statuette on the force meter completely immersed in the water. The force meter showed a value 17 N. What is the volume of the statuette? - Tiles

How many square tiles with the content 121 cm^{2}has to be ordered for the paving of the square room with a side length of 2.75 meters? - Wheel

Diameter of motocycle wheel is 52 cm. How many times rotates wheel on roand long 2 km? - Tram

In the three-part tram went 206 passengers in front of others, 226 after others and in the middle half of all. How many passengers went in tram total? - Isosceles right triangle

Contents of an isosceles right triangle is 18 dm^{2.}Calculate the length of its base. - Prism

Calculate the height of the prism having a surface area 448.88 dm² wherein the base is square with a side of 6.2 dm. What will be its volume in hectoliters? - Grass garden

Mr. Grass would itself be mowed garden for 5 hours. His son Michael could do it for 7 hours. They agreed that they wake up at 5 am and begins to mow together. Ms. Grass needs drive into town at 8.30. Michael says that at that time they're done with work.. - 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? - 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 ? - Mason with assistant

Mason had to complete the work in 10 days. Two and a half days later his assistant arrived. Together they completed the work in next three and a half days. How many days would he need an assistant for the same work? - 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 - Tree shadow

The shadow of the tree is 16 meters long. Shadow of two meters high tourist sign beside standing is 3.2 meters long. What height has tree (in meters)? - 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? - New refrigerator

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

Draw a square ABCD whose diagonals have a length of 6 cm

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