Math practice for 13 year olds - page 426 of 429

Number of problems found: 8567

Density - simple example
Material of density of 1189 kg/m³ occupies a container volume of 64 cm³. What is its mass?
Floating barrel
The barrel (cylinder shape) floats on water, the top of the barrel is 18 dm above water, and the width of the surfaced barrel part is 34 dm. The barrel length is 12 dm. Calculate the volume of the barrel.
Circle arc
The circle segment has a circumference of 9.08 km and 58.99 km² area. Calculate the radius of the circle and the size of the central angle.
3y inflation
The price of the cookie rise in the first year by 2%, the second year fell by 6%, and in the third year increased by 17%. Calculate the average annual increase in the price of the cookie.
Inflation
Once upon a time, the tsar owned a money printer and printed and printed. Printing money prices went up in the first year 2.7 %, in the second 2.1%, in the third 3.6%, and in the fourth 5.4%. Then tsar failed in the election. Calculate the average annual
Circles
Three circles of radius 30 cm, 28 cm, and 37 cm are mutually tangent. What is the triangle perimeter whose vertices are the circles' centers?
Insurance
The house owner is insured against natural disasters and pays 0.05% annually of the value of the house 88 Eur. Calculate the value of the house. Calculate the probability of disaster if you know that 50% of the insurance is to pay damages.
Two doctors
Doctor A will determine the correct diagnosis with a probability of 89% and doctor B with a probability of 75%. Calculate the probability of proper diagnosis if both doctors diagnose the patient.
Slovak broad track
Once upon a time, we learned in school that the Ukrainian have "wider" tracks than ours because they have less tolerable ground. In truth, decide only the area of sleepers, no track gauge. Calculate how many millimeters our track is 1435 mm, different fro
Present
The gift box has a rectangular shape with dimensions of 8×8×3 cm. Miloslav wants to cover it with square paper with sides of 18 cm. How much paper was left to him?
Monkey
The monkey fell into 20 meters deep well. Every day it climbs 3 meters, at night it drops back by 2 m. On what day it gets out from the well?
Mine
The wheel in the traction tower has a diameter of 4 m. How many meters will perform an elevator cabin if the wheel rotates in the same direction 89 times?
Clocks
How long will a path of the end of the clock's minute-hand long 23 cm for 340 minutes? How long will we walk at the same time hour-hand?
Cone in cylinder
The cylinder is an inscribed cone. Find the ratio of the volume of the cone and cylinder. Please write the ratio as a decimal number and as a percentage.
Cone in cube
The cube is an inscribed cone. Determine the ratio of the volume of the cone and cube. Please write the ratio as a decimal number and as a percentage.
Kites
Boys run kites on a cable of 68 meters long. What is the kite altitude if the angle from the horizontal plane is 72°?
Ladislav in Amsterdam
Laco went (was sent) to a conference in Amsterdam for a reward. The conference fee was € 1702. Calculate how many books Ladislav could buy at the price of 30 and 28 euros if he doesn't want to fill the whole home library, and he can buy only 59 books
Chess
How many ways can you select 4 fields on a classic chessboard with 64 fields so that fields don't have the same color?
Maximum area of rhombus
Calculate the interior angles at which the equilateral rhombus has a maximum area.
Lunch for free
Gastro tickets are "free," so they should be retained. Many employees in Slovakia approve of free goods, such as a free gastro ticket per day of work. The company issuing gastro tickets receives a 4.3% fee on the total amount of money spent on tickets. Ca

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