Maths practice for 14 year olds - page 291 of 382

Number of problems found: 7626

925 USD
Four classmates saved an annual total of 925 USD. The second saves twice as the first, the third 35 USD more than the second, and the fourth 10 USD less than the first. How does USD save each of them?
Number probability
There are numbers from 1 to 20 in the hat. What is the probability that we will pull out from the hat: a / one-digit number b / prime number c / number greater than 11 d / a number divisible by six Thank you
Alcohol preparation
We want to prepare 200 g of 64% alcohol. We have a sufficient amount of 80% and 45% alcohol. How many of which will we need?
Exponent equation
Determine what x equals in the equation: (256^x): 10^-1 = 40
Rectangle diagonal
Calculate the diagonal length of a rectangle whose length is 3 cm greater than its width and whose circumference is 18 centimeters.
Algebrogram
Solve algebrogram: mama+anna=vari How many solutions are?
Trapezoid bases
In a trapezoid, the difference between the bases is 6 cm. Calculate the lengths of the bases of the trapezoid when its height is 8 cm and the area of the trapezoid is 168 cm².
Spray - mixture
4 per mille of active ingredient is needed per 6 liters of water to prepare sprays. How many milliliters of active substance do we add to the sprays?
Dividends
The three friends divided the win by the invested money. Karlos got three-eighths, John 320 permille, and the rest got Martin. Who got the most, and which got the least?
Diamond diagonal
The diamond has an area of 94.24 square meters and one diagonal of 7.6 cm. Calculate the length of the second diagonal.
Gold extraction
There are 1.2 per mille of gold in the rock. How many grams of gold will they get from 45 tons of raw material?
Tank dimensions
The block of goods has dimensions of 2.5 m, 4.2 m, and a height of 180 cm. It is filled to two-thirds of the volume. How many hectoliters of water are in it? How many m² of the tank is soaked with water?
Active substance
There are 5 ml of active substance in a 600 ml spray. How much is it per mille?
Wire length
What was the length of an iron wire with an area of 3 cm² if its resistance was 15 ohms? Iron (Fe) resistivity is 0.0996 x 10 at -6 Ohm/meter.
Collection weight
Thomas brought the collection 20 percent less than Michael. Philip brought half of what Tomas did. Together, they brought 52.8 kg. How much did he bring?
Interest rate
At what annual interest rate would we get an interest of 60 euros on a deposit of € 6,000 for three months?
Two numbers
The sum of two numbers is 10,000, and one is four times larger than the other. What are two numbers?
Break percentage
Students have classes from 8:00 to 12:30. One 15-minute break and three 10-minute breaks between lessons. What percentage of teaching is breaking?
Atomic diameter
The diameter of the atomic nucleus is 10 to -12 cm. How many atoms would fit on a 1 mm line if they could be arranged close together?
Sun density
The volume of the Sun is 1.4x10 per 18 km cubic, and the weight is 2x10 per 30 kg. What is the average density? (in kg/m cubic)

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