Maths practice for 14 year olds - page 289 of 381
Number of problems found: 7617
- Resistivity 3983
What was the length of an iron wire with an area of 3cm² if its resistance was 15 ohms? Iron (Fe) resistivity is 0.0996 x 10 at -6 Ohm/meter. - Collection 3977
Tomáš brought the collection 20 percent less than Michal. Filip 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? - Numbers 3974
The sum of two numbers is 10,000, and one is four times larger than the other. What are two numbers?
- Percentage 3971
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? - Diameter 3962
The diameter of the atomic nucleus is 10 to -12cm. How many atoms would fit on a 1 mm line if they could be arranged close together? - Density 3961
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) - Direction 3958
In the direction of Hradec Králové, a car left Prague at 8 hours at a 50 km/h speed. At 8 hours and 30 minutes, another car followed him at an average 70 km/h speed. How long will it take to catch up with the first car? - Calculate 3956
The rotating cylinder has a diameter of 14 cm and a surface of 1,186.92 cm square. Calculate the height of the cylinder.
- Dimensions 3950
Calculate the solid diagonal of a block whose dimensions are: a = 3cm, b = 5, c = 7cm. Find its volume as well. - Expression 3949
Determine what y equals in expression (16^y): 5 = 0.4 - Percents of percentages
Calculate: (a) 5% of 25% of 85 b) 4% of 20% of 1500 c) 83% of 20% of 25 d) 0.3% of 70% of 90 - Determine 3945
Determine the sum of the square roots of the number 25. - Centimeters 3940
Calculate the solid diagonal of a cube whose surface equals 24 square centimeters.
- Three-day 3939
Petr got a three-day part-time job for the holidays. On the first day, he earned 1/4 of the total amount. On the second day, 2/5 of the last two days, and on the third day, he made CZK 450. How much did you earn in total? - Area of a cube Calculate the surface area of a cube if its volume is equal to 729 cubic meters.
- Glass
How many glasses are needed to produce glass with a base of a regular 5-gon if one base triangle in the base is 4.2 square cm and the height is 10 cm? - Z9-I-4
Kate thought of a five-digit integer. She wrote the sum of this number and its half in the first line of the workbook. Write a total of this number and its fifth on the second line. She wrote a sum of this number and its one nines on the third row. Finall - Tunnels
Mice had built an underground house consisting of chambers and tunnels: • each tunnel leading from the chamber to the chamber (none is blind) • from each chamber lead just three tunnels into three distinct chambers, • from each chamber, mice can get to an
16% of the unknown number equals the square root of the number 25. Find this unknown number.Do you have unsolved problem that you need help? Ask a question, and we will try to solve it. Solving math problems.
