Math practice for 13 year olds - last page
Number of problems found: 8720
- Two numbers
Find two numbers whose difference and the ratio are 4. - Acid
A barrel contains 79 litres of 60% acid. What percentage of acid remains when 4 litres are removed and replaced with the same amount of water? - Election mathematics
In elections, 8 political parties received the following shares of votes: strana A ; 56 % strana B ; 11.9 % strana C ; 11.7 % strana D ; 8.8 % strana E ; 6.3 % strana F ; 5.1 % strana G ; 0.2 % Calculate what share each party would obtain in parliament if - Cu thief
A thief stole 25 metres of copper wire with a cross-sectional area of $s mm². Calculate how much money the thief receives by selling it as scrap if copper fetches 5.1 EUR/kg. The density of copper is 8.96 t/m³. - Bicycle wheel
A bicycle wheel has a diameter of 60 cm. Approximately how many times does the wheel rotate on a 2.5 km trip? - N-gon angles
What is the sum of the interior angles of an 8-gon? What is each interior angle of a regular convex 8-gon? - Slope of track
Calculate the average gradient (in per mille and in degrees) of the railway tracks between Prievidza (309 m above sea level) and Horná štubňa (624 m above sea level), given that the track is 37 km long. - Rotation of the Earth
Calculate the linear speed of the Earth's surface at a latitude of 34.5°. Assume a globe with a radius of 6378 km. - Right triangle Alef
The obvod of a right triangle is 120 cm, and the hypotenuse is 51 cm long. Determine the lengths of the legs. - Temperature calculus
Calculate the percentage of temperature stúpla if changed from 3°C to 7°C. - Phone numbers
How many 9-digit telephone numbers can be formed from the digits 0, 1, 2, ..., 9 if no digit is repeated? - Crossroads
A passenger car and an ambulance approach a rectangular intersection, and the ambulance turns off. The passenger car is moving at 39 km/h and the ambulance at 41 km/h. Calculate the relative speed of the ambulance with respect to the car. - Required reserves
Calculate the minimum amount of money the bank must hold in cash from your deposit 2750 Eur. How much money is ideally created in the banking system from your deposit if the level of minimum reserve requirement is 2.15%? Consider fractional reserve system - Right triangle
Calculate the unknown side b, all interior angles, the perimeter, and the area of a right triangle if a = 10 cm and hypotenuse c = 16 cm. - Engineer bug
Comical errors, disputes and plots arise when converting physical units. The core of today's dispute was the price of natural gas. The unit was changed - from the natural unit of cubic meter of gas to the unit kWh. The goal was to be able to compare the p - Profitable bank deposit 2012
Calculate the real value lost by depositing €11200 in a bank for 4 years at an interest rate of 2% p.a., with a 19% tax on interest and an annual inflation rate of 3.7%. (Calculate what you lose by leaving money in a bank account at a negative real intere - Eiffel Tower
The Eiffel Tower in Paris is 300 metres high and made of steel. It weighs 8,000 tonnes. If a model of the tower made of the same material weighs 2.8 kg, how tall is it? - Speed of Slovakian trains
Rudolf took the train from the station 'Nitra' to 'Nové Zámky'. In the train timetables found train Os 5004 : km 0 Prievidza 14:25 4 Koš 14:30 14:31 9 Nováky 14:36 14:37 13 Zemianske Kostoľany 14:42 14:43 16 Bystričany 14:47 14:48 19 Oslany 14:51 14:51 23 - The game of blind man's buff
The Slovak levy system deducts contributions from the gross wages of employees. It has two components — the part paid by the employee and the part paid by the employer. Suppose that the employer's total labour cost (super-gross wage) is 21% more than the - Greek railwayman
Lewis has worked for Slovak Railways since 2000. His salary is 950 €. His colleague Evgenias has worked for Greek State Railways since 1984 and earns 5700 € per month. Calculate: a) how many times more does Evgenias earn than Lewis? b) how many times more
Do you have homework that you need help solving? Ask a question, and we will try to solve it. Solving math problems.
