Maths practice for 14 year olds - page 138 of 361

Number of problems found: 7217

Engine performance
The car's engine develops a power of 1800 N. Find its performance if it travels evenly on a horizontal path at 48 km/h.
Five-digit number
Anna thinks of a five-digit number not divisible by three or four. If he increments each digit by one, it gets a five-digit number divisible by three. If he reduces each digit by one, he gets a five-digit number divisible by four. If it swaps any two digi
Cage gravitational energy
Find the potential gravitational energy of a 2000 kg tow cage relative to the bottom of an 850 m deep draw pit when the cage is on the surface.
G Force, mass
A car with a weight of 20 kN travels at a speed of 54 km/h. What is its kinetic energy?
Nail work
What work do we do if we pull out a 58 mm nail with an average force of 350 N?
Biology test
Peter Šťastný did not manage to study for the biology test due to urgent matters. In the test, for every correctly solved task there were 10 points, for a wrongly solved task 5 points were subtracted, one could also not answer, for which there were 0 poin
Happy marriage
Jan and Mary have been in a happy marriage for several years. Jan's age is written in the same numbers as Mary's, only in reverse order. Their ages differ by just a fifth of Mary's. Jan is older. How old is Jan, and how many is Mary?
Perpendicular leg
Calculate the area of a right triangle whose longer perpendicular is six dm shorter than the hypotenuse and three dm longer than the shorter perpendicular.
She showed the PC
Sabína wrote down how many hours a day she sat at the PC. Dana illustrated the data using a radar chart. Sabína spent approximately 100% more time at the PC on weekends than on weekdays. Saturday: 5 hours, Sunday: 4 hours. During the week: Monday 1 hour,
Pedestrian cyclist meeting
Cities A and B are 36 km apart. A pedestrian leaves town A at a speed of 6 km/h to place B. A cyclist leaves town B simultaneously at a speed of 24 km/h to town A. In how many hours and at what distance will they meet? Write the result in minutes.
Tests
To obtain a grade A, Patrick must score an average of at least 70 on five tests. If his average mark for the four tests is 68, what is the lowest mark he can get on his fifth test and still obtain a grade A
Shot casting
How many shots with a diameter of 2 mm can a gunsmith cast from 1 kg of lead? The density of lead is 11.4 g / cm³
Ball drawing probability
We have five red and seven white balls in a hat. What is the probability of pulling: a) a red ball? b) a white ball?
No solutions
Why does the equation 9-2x-9-16x=-14x-7-4x-11 have no solutions?
The difference 2
The difference between the two numbers is 25. The smaller number is 1/6th of the larger number. What is the value of the smaller number?
Reindeer penguin
There were 10 more reindeer than penguins in the ice kingdom. But the lousy witch captured a third of the reindeer. There were only 22 reindeer left in the kingdom. How many penguins lived in the ice kingdom before the evil witch came?
The sides
The sides of a right triangle form an arithmetic sequence. The hypotenuse is 24 cm long. Determine the remaining sides of the triangle.
Binary words
How many 10-bit words can be created with precisely four units (e.g., 1111000000)?
Land acre purchase
The price for 1 acre of good land is 300 gold coins, and the price for 7 acres of bad land is 500 gold. The buyer bought a total of 100 acres for 10,000 guilders. How many acres of good and how many acres of bad land did he buy?
A plane vs. sphere
The intersection of a plane is 2 cm from the sphere's center, and this sphere is a circle whose radius is 6 cm. Calculate the surface area and volume of the sphere.

Do you have homework that you need help solving? Ask a question, and we will try to solve it. Solving math problems.