Math practice for 13 year olds - page 51 of 364
Number of problems found: 7272
- Probability 82362
If we roll one die, what is the probability of rolling a number other than 1? - Purchased 82340
The company secretary bought stamps worth CZK 20 and CZK 15. The total number of purchased stamps is 120, and the secretary paid a total of 2265 CZK. How many stamps worth 15 CZK did she buy? - Landscape 82339
Soňa is sitting on the train, looking out the window, and what she doesn't see is that the landscape runs backward at a constant speed of 160 km/h, and on the side track, the train is seemingly backing up at a constant speed of 40 km/h. Sonia stops and wo - Liters 82335
We have 4.5 liters of syrup, and 80% is juice. How many liters of juice were there?
- Repeated 82330
How many 5-digit numbers can we create from the number 1,2,3,4,5 if the one's place is to have the number 5? (digits must not be repeated.) - Thermal energy
From the formula for calculating thermal energy Q=m*c*t, express t and calculate by how many °C 2kg of water must be heated to increase its energy by 126kJ - Arithmetic 82287
If the arithmetic mean of the numbers a1, a2, a3, a4, and a5 is the number A, the arithmetic mean of the numbers a1, a2, a3, and a4 is the number B, then what is a5 equal to? - Basis 82283
What is the basis if 40% of the base is €320? - Calculate 82282
Calculate the sizes of the interior angles in the triangle whose vertices are the points marked by the numbers 1, 5, and 8 on the clock face.
- Five-digit 82257 Determine the number of all five-digit natural numbers in which every two digits are different in decimal notation.
- Distance 82240
On a map with a scale of 1:100,000, two lakes are 20 cm apart. What is their distance on a map with a scale of 1:40,000? - One-twentieth 82239
Peter and Honzo decided to build the building as quickly as possible. They built one-twentieth of the building in ten minutes. After 20 minutes, three more friends joined. Everyone was building at the same pace. How many minutes did it take to build the s - Capacity 82231
There were 60 people in the stadium, which was 30% of capacity. How many people can fit in the stadium? - Two-hundred-liter 82230
What is the weight of a two-hundred-liter barrel with ethanol if the empty barrel weighs 50 kg?
- Centimeters 82219
What is the height of a box whose base edges are 50 mm long and 0 full six dm if its volume is 120 cubic centimeters? - Acceleration 82217
The car has a speed of 5 m/s and accelerates to 35 m/s in 12 seconds. Calculate the acceleration of the car at a speed of 34.5 m/s. - Diameter 82212
How many meters of copper wire with a diameter of d=3 mm will be produced from 60 kg of copper scrap if the specific gravity of copper is p=9g/cm³? - Discovered 82210
At the dance party, the organizer discovered that 168 different dance pairs could be formed from girls and boys. How many boys are there at the dance if there are 12 girls? - Excavators 82208
Two excavators dig a pit in 12 days. How much shorter will this job take if 8 excavators dig the hole? In 3 or 9 days?
The pole is stuck vertically into the ground. The protruding length is 1m. What is the length of the shadow cast when the sun is just 50° above the horizon?Do you have unsolved problem that you need help? Ask a question, and we will try to solve it. Solving math problems.
