Maths practice for 14 year olds - page 169 of 375

Number of problems found: 7500

Window door replacement
We ordered two parties of workers to replace the windows and doors. The first group would complete the task in 15 days. The second in ten days. How many days will they be able to exchange it together?
Tower roof area
The administrator of the castle is trying to estimate how many square meters of sheet metal will be needed for the new roof of the tower. The roof has the shape of a cone. The castle administrator knows that the tower's diameter is 4.6 meters and its heig
Block diagonal calculation
The volume of the block is 144 cm³. The base measures 3 cm and 4 cm. How big is the body diagonal?
Triangular prism
Calculate the surface of a regular triangular prism; the base's edges are 6 cm long, and the height of the prism is 15 cm.
Five tractors
Five tractors plow the fields in 4.8 hours. How long will it take to plow the field when, after an hour and a half of work, two tractor drivers have been called up for another task?
Meeting speed calculation
Adam and Eve live 20 km apart. They are going to a meeting. Adam moves at a speed of 2 km/h faster than Eva. They will meet in one and a half hours. Determine their speeds.
Two hemispheres
In a wooden hemisphere with a radius r = 1, the carpenter created a hemispherical depression with a radius r/2. The bases of both hemispheres lie in the same plane. What is the surface of the created body (including the surface of the depression)?
Pyramid edge calculation
We know a regular quadrilateral pyramid's base diagonal length of u = 4 cm. The height of the pyramid is v = 5cm. Calculate the size of the side edge and the base edge of the pyramid.
Computer banknote payment
Dad paid for the computer with banknotes worth 500 and 1,000 CZK. The number of banknotes was 56, and the price of the computer was CZK 44,000. How many banknotes did he have?
Wire fence
The wire fence around the garden is 160 m long. One side of the garden is three times longer than the other. How many meters do the individual sides of the garden measure?
Park fountain percentage
In the shape of a rectangle, the city park, measuring 125 x 12 m, has a circular fountain with a diameter of 10 m. What percentage of this fountain represents the total area of the park?
Ton kilogram percentage
How many kilograms is 24% of 30 tons?
Quiz or test
I have a quiz with 20 questions. Each question has four multiple-choice answers, A, B, C, D. THERE IS NO WAY TO KNOW THE CORRECT ANSWER OF ANY GIVEN QUESTION, but the answers are static, in that if the "correct" answer to ; 1 = C, then it will always be e
The half life
The half-life of a radioactive isotope is the time it takes for a quantity of the isotope to be reduced to half its initial mass. Starting with 145 grams of a radioactive isotope, how much will be left after three half-lives?
Average height
There are twice as many girls in the class as there are boys. The average height of girls is 177 cm, and boys 186 cm. What is the average height of students in this class?
Class girl percentage
In the 7A class, the ratio of boys to girls is 2:3. What percentage of the class are girls?
Trapezoid section area
The cross-section of the railway embankment is an isosceles trapezoid, the bases of which are in a ratio of 5:3. The arms have a 5 m embankment height v = 4.8 m. Calculate the section area S.
Difference - altitude
The distance as the crow flies between Dolní and Horní Ves is 3 km, and the steady climb is 5%. What is the height difference between Horní and Dolní Ves rounded to the nearest meter?
Half of halves
We cut half of the square off, then half of the rest, etc. Five cuts we made in this way. What part of the area of the original square is the area of the cut part?
Production cost reduction
The cost of production of a particular product decreased first by 15% and then by 10% of the new amount. After this reduction, it cost CZK 153. What were the original production costs?

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