# Examples for 8th grade - page 76

- Joshka

Joshka had € 15. Mama took him 15%. How many had left? - Password dalibor

Kamila wants to change the password daliborZ by a) two consonants exchanged between themselves, b) changes one little vowel to such same great vowel c) makes this two changes. How many opportunities have a choice? - Donuts

In the dining room at one table sit Thomas, Filip and Martin. Together they eat 36 donuts. How many donuts eaten everyone, when Filip ate twice as much as Thomas and Martin even half over Filip? - Unknown number 24

f we add 20, we get 50% of its triple. What is this unknown number? - Buttons

Shirt has 6 buttons, blouse has 4 buttons. All buttons are 176. Shirts and blouses are together 36. How many are the shirts and blouses? - 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. - Combinations of sweaters

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

Denis and Zdeno together have 97 coins. If Denis had 4 coins less than he has now, the number of the coins would be in the ratio 14: 17. Determine the number of coins owned by Denis and Zdeno. - Bath salts

Bath salt A weighs 900 grams and costs 36,40 CZK. Bath Salts B weighs 1000 grams, but costs 85 CZK. How much is a bath salt A cheaper than B one? - Disc

Circumference of the disk is 78.5 cm. What is the circumference of the circular arc of 32° on the disc? - Fuel economy

How many kilometers is sufficient petrol in the cylinder fuel tank with a diameter 40 cm and the base of tank length 1 m, when it is filled to 60% and if the car consume 15 liters per 100 km? - Percent

Calculate how many % is the number 26.25 less than the number 105. - Pharmacy

The pharmacy add to 3 liters of 95-percent alcohol 5 liters of 38.04 percent alcohol. How many percent pharmacy got? - 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. - 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. - Trio 2

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

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