# Examples for 8th grade - page 70

- Sphere vs cube

How many percent of the surface of a sphere of radius 12 cm is the surface of a cube inscribed in this sphere? - Four swords

Obelix has three helmets, four swords and five shields. How many swords must make at the blacksmith forge Metallurgix to be able to walk another 90 days in unique armor? - Wallet

From the money that was in my Maria wallet she spent a fifth on the first purchase. From remain money she could buy 2 kg of strawberries. But she bought only 1.5 kg for 60 Kc. How much money was Marie originally in her wallet? - Painter

How many euros we will pay for repainting the room shaped cuboid with a length of 4.5 meters, width of 2.5 meters and a height of 3 meters, if for 1 m^{2}with paint we pay € 1.5? - Lines

How many lines can be draw with 8 points, if three points lie on one line and the other any three points do not lie on the same line? - Trucks

Truck take you the some amount of clay in 30 hours. Second truck in 40 hours. Trucks carted the clay away some time together then the second truck broke down and the first one completed the job in five hours. What time worked together? - Runner

Peter ran a speed of 12.4 km / h. After 45 minutes running he had a hiatus. The track is 31 km long. How many kilometers he still to run if he still running at the same speed? - Gasoline

For nearly full tank of 40 liters of gasoline chauffeur paid 54 euros. How many euros it will cost to go 250 km long if the car has an average fuel consumption 7 liters per 100 kilometers? - Odd numbers

The sum of four consecutive odd numbers is 1048. Find those numbers ... - Candies

If Alena give Lenka 3 candy will still have 1 more candy. If Lenka give Alena 1 candy Alena will hame twice more than Lenka. How many candies have each of them? - Nuts

Peter has 49 nuts. Walnuts have 3 more than hazelnuts and hazelnut 2 over almonds. Determine the number of wallnuts, almonds and hazelnuts. - Boys and girls 2

The ratio of boys to girls in math club is 4:3 . After 8 more girls joined the Club, the ratio become 1:1. How many members are there in the club now? - Mow the lawn

Dano would mow the lawn in 12 hours and Milada in 16 hours. How long will take the lawn mow together? - Driver

The driver of the supply car reckoned that at the average speed of 72 km/h arrives to the warehouse for 1 1/4 hours. After 30 km however unintentionally drove to the gas station and have ten minutes delay. At what average speed would have to go the rest. - Octagonal mat

Octagonal mat formed from a square plate with a side of 40 cm so that every corner cut the isosceles triangle with leg 3.6 cm. What is the content area of one mat? - Positive number z

Positive number z is 10% greater than the number y. How many % is y smaller than z? Report the result rounded to one decimal place. - Rectangle 3-4-5

The sides of the rectangle are in a ratio of 3:4. The length of the rectangle diagonal is 20 cm. Calculate the content of the rectangle. - Divisibility

Write all the integers x divisible by seven and eight at the same time for which the following applies: 100 - Four circles

1) Calculate the circle radius if its area is 400 cm square 2) Calculate the radius of the circle whose circumference is 400 cm. 3) Calculate circle circumference if its area is 400 cm square 4) Calculate the circle's area if perimeter 400 cm. - Freezer

The freezer has the shape of a cuboid with internal dimensions of 12 cm, 10 cm, 30 cm. A layer of ice of 23 mm thick was formed on the inner walls (and on the opening) of the freezer. How many liters of water will drain if we dispose the freezer?

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