# Examples for 8th grade - page 76

- Cube surface area

The surface of the cube was originally 216 centimeters square. The surface of the cube has shrunk from 216 to 54 centimeters sq. Calculate how much percent the edge of the cube has decreased. - Pharmacy

The pharmacy add to 3 liters of 95-percent alcohol 5 liters of 38.04 percent alcohol. How many percent pharmacy got? - Percentage - fractions

About what percentage we must increase number 1/6 to get number 1/3? - Circle - simple

Calculate the area of a circle in dm^{2}, if its circumference is 31.4 cm. - Cuboid - ratios

The sizes of the edges of the cuboid are in the ratio 2: 3: 5. The smallest wall have area 54 cm^{2}. Calculate the surface area and volume of this cuboid. - Trio 2

Decide whether trio of numbers is the side of a right triangle: 26,24,10. - Combinations of sweaters

I have 4 sweaters two are white, 1 red and 1 green. How many ways can this done? - Common cylinder

I've quite common example of a rotary cylinder. Known: S1 = 1 m^{2}, r = 0.1 m Calculate : v =? V =? You can verify the results? - Cylinder surface area

Volume of a cylinder whose height is equal to the radius of the base is 678.5 dm^{3}. Calculate its surface area. - Square roots

What is equal to the product of the square roots of 295936? - Blueberries 2

Lenka and Martin collected eight liters of blueberries in two hours. How long will take to collect blueberries by Lenka itself, if we know that she collect all 2.5 hours less than Martin? - Trapezoid MO-5-Z8

Trapezoid KLMN has bases 12 and 4 cm long. The area of triangle KMN is 9 cm^{2}. What is the area of the trapezoid KLMN? - Cycling trip

At 8 am started a group of children from the camp to day cycling trip. After 9:00 weather deteriorated sharply and the leader decided to send for the children bus on the same route, which started at 10 hours. For how long and at what distance from the camp - 2d shape

Calculate the content of a shape in which an arbitrary point is not more than 3 cm from the segment AB. The length of the segment AB is 5 cm. - Sales off

Calculate what was the original price of the good, if the price after discount 25% and the subsequent rise of 20% is 400 USD. - Flowerbed

Family cultivated tulips on a square flower bed of 6 meters. Later they added the square terrace with a side of 7 meters to their house. One vertex of the terrace lay exactly in the middle of a tulip bed, and one side of the terrace divided the side of the - Log

Worker cut his thick log to 6 pieces for 30 min. How long he cut log to 12 pieces? - Addends

Number 118 divide into two addends, so first addend is 69 greater than 75% of the second addend. - Theatro

Theatrical performance was attended by 480 spectators. Women were in the audience 40 more than men and children 60 less than half of adult spectators. How many men, women and children attended a theater performance? - Potatoes

Daniela and Michael would jointly dug potatoes for 7.5 hours. But if Daniela was working alone she would take 2.5 hours more as if he were working with Michael. Determine how much for the work done by Michael himself and how much Daniela herself.

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