Examples for 8th grade - page 76

1. Cylinder surface area Volume of a cylinder whose height is equal to the radius of the base is 678.5 dm3. Calculate its surface area.
2. 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?
3. Trio 2 Decide whether trio of numbers is the side of a right triangle: 26,24,10.
4. Trapezoid MO-5-Z8 Trapezoid KLMN has bases 12 and 4 cm long. The area of triangle KMN is 9 cm2. What is the area of the trapezoid KLMN?
5. 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?
6. Common cylinder I've quite common example of a rotary cylinder. Known: S1 = 1 m2, r = 0.1 m Calculate : v =? V =? You can verify the results?
7. Square roots What is equal to the product of the square roots of 295936?
8. 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.
9. 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
10. 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.
11. Pumps Five pumps pumped 1,800 hl of water for 3 hours. How many hectoliters of water pump same two powerful pumps for six hours?
12. Base, percents, value Base is 344084 which is 100 %. How many percent is 384177?
13. 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.
14. Log Worker cut his thick log to 6 pieces for 30 min. How long he cut log to 12 pieces? Number 118 divide into two addends, so first addend is 69 greater than 75% of the second addend.
16. Z7-I-4 stars 4949 Write instead of stars digits so the next write of product of the two numbers to be valid: ∗ ∗ ∗ · ∗ ∗ ∗ ∗ ∗ ∗ ∗ 4 9 4 9 ∗ ∗ ∗ ∗ ∗ ∗ 4 ∗ ∗
17. Trams Two trams started at the same time from the same place. One tram journey takes 30 minutes and the second 45 minutes to its final stop. How long will trams meet again?
18. Megapascals What is the area of crosssection of the piston, if the force of 300 kN produces a pressure of 5 MPa?
19. Line segment Cut a line segment of 15 cm into two line segments so that their lengths are in ratio 2:1. What length will each have?
20. Assistant Assistant rewrote 15% of the entire manuscript in 12 hours. How many hours must still write to rewrite the rest of the manuscript?

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