# Examples for 8th grade - page 71

- Reducing number

Reducing the an unknown number by 28.5% we get number 243.1. Determine unknown number. - The tram

The tram is moving with acceleration a = 0.3m/s2. How long it will pass the first meter of track? How long does it take 10 meters. What is its speed at the end of the 10 meters track? - Dining room

The dining room has 11 tables (six and eight seats). In total there are 78 seats in the dining room. How many are six-and eight-seat tables? - Container

The container has a cylindrical shape the base diameter 0.8 m and the area of the base is equal to the area of the wall. How many liters of water can we pour into the container? - Store

Peter paid in store 3 euros more than half the amount that was on arrival to the store. When he leave shop he left 10 euros. How many euros he had upon arrival to the store? - Truncated cone 5

The height of a cone 7 cm and the length of side is 10 cm and the lower radius is 3cm. What could the possible answer for the upper radius of truncated cone? - Rectangle - sides 4

Perimeter of the rectangle is 72 cm. Calculate the length of the sides that are in the ratio 3:5. - Internal angles

One internal angle of the triangle JAR is 25 degrees. The difference is the size of the two other is 15°. Identify the size of these angles. - Dried apples

How many kilograms of fresh apples id needed to 120 kg of dried apples when from 0.4 tons of fresh apples we get 75 kg of dried apples? - Three friends

Three friends divided the profit 104,650 CZK, so that for every 4 CZK, which got the first friend equals 5 crowns for second and for every 9 CZK, which got the second equals 16 CZK for third. Question: Who got the most and how much. - Gasoline tank cylindrical

What is the inner diameter of the tank, which is 8 m long and contains 40 cubic cubic meters of gasoline? - Unknown number 10

Number first increased by 30%, then by 1/5. What percentage we've increased the original number? - Six years

In six years Jan will be twice as old as he was six years ago. How old is he? - Divisibility by 12

Replace the letters A and B by digits so that the resulting number x is divisible by twelve /find all options/. x = 2A3B How many are the overall solutions? - Sum 10

What is the probability that two dice throw twice in a row will result the sum of 10? - Steamer

At 6 hours 40 minutes steamer sailed from the port at speed 12 km/h. At exactly 10 hours started sail motorboat at speed 42 km/h. When motorboat will catch steamer? - Dollars

Mama split 760 dollars Jane, Dane and Eva as follows: Jane got three times more than Dane and Dane and got 40 more than Eva. How much does get each of them? - Wood cuboid

What is the weight of the wood cuboid 15 cm, 20 cm, 3 m if 1 m^{3}wood weighs 800 kg? - Cablecar

Funicular on Petrin (Prague) was 408 meters long and overcomes the difference 106 meters in altitude. Calculate the angle of climb. - Three digits number 2

Find the number of all three-digit positive integers that can be put together from digits 1,2,3,4 and which are subject to the same time has the following conditions: on one positions is one of the numbers 1,3,4, on the place of hundreds 4 or 2.

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