# Examples for 8th grade - page 78

- Two numbers

The sum of the two numbers is 1. Find both numbers if you know that half of the first is equal to one seventh of the second number. - Four ropes

TV transmitter is anchored at a height of 44 meters by four ropes. Each rope is attached at a distance of 55 meters from the heel of the TV transmitter. Calculate how many meters of rope were used in the construction of the transmitter. At each attachment. - Cost reduction

Two MP3 players whose price was equal to originally have been discounted the first by 20%, the second by 35%. After the price reduction was the difference in their prices 750, - CZK. What was the original price of each of the two players? - 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? - 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. - Unknown number

Identify unknown number which 1/5 is 40 greater than one tenth of that number. - 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? - Right triangle ABC

Calculate the perimeter and area of a right triangle ABC, if you know the length of legs 4 cm 5.5 cm and 6.8 cm is hypotenuse. - Fuel mileage

You have 3/8 tank of fuel. Estimate fuel consumption @ 6mpg. Estimate speed @ 50mph. Your fuel tank holds 200 gals. Figure out fuel mileage. - Is right triangle

Decide if the triangle XYZ is rectangular: x = 4 m, y = 6 m, z = 4 m - Glass

Trader ordered from the manufacturer 200 cut glass. The manufacturer confirmed the order that the glass in boxes sent a kit containing either four or six glasses. Total sent 41 boxes. a) How many boxes will contain only 4 glasses? b) How many boxes will co - Cruise liner

Cruise liner runs along the river between points A and B. The journey downstream takes 40 minutes 1 hour upriver. The flow rate of the river is 3 km/h. What is the speed of cruise liner? - Combinations of sweaters

I have 4 sweaters two are white, 1 red and 1 green. How many ways can this done? - Rabbits 3

Viju has 40 chickens and rabbits. If in all there are 90 legs. How many rabbits are there with Viju? - Percentages

Calculate the percentages to two decimal places: a / 15 min in 4 hours B / 35 cm^{2}of 12.5 dm^{2}c / 2dm2 of 400 cm^{2}D / 0.2 liters from 2.2 liters - TVs

Production of television sets increased from 3,500 units to 4,200 units. Calculate the percentage of production increase. - Tickets

On the football tournament ticket cost 45 Kc for standing and 120kč for sitting. Sitting spectators was 1/3 more than standing. The organizers collected a total 12 300 Kc. How many seated and standing seats (spectators)? - Shell of cylinder

Calculate the content of shell the 1.6 m height cylinder with a base radius of 0.4 m. - Isosceles trapezoid

Calculate the circumference and the contents of the isosceles trapezoid if you know the size of the bases is 8 and 12 cm and the size of the arms is 5 cm. - Sugar 9

150 kg of sugar beet yields 24 kg of sugar. From how many tons of sugar beet can be obtained three tons of sugar?

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