New math problems
- Sun rays
If the sun's rays are at an angle 60° then famous Great Pyramid of Egypt (which is now high 137.3 meters) has 79.3 m long shadow. Calculate current height of neighboring chefren pyramid whose shadow is measured at the same time 78.8 m and the current hei
- Trapezoid MO-5-Z8
Trapezoid KLMN has bases 12 and 4 cm long. The area of triangle KMN is 9 cm2. What is the area of the trapezoid KLMN?
- Percentages 5
$5.25 is 7 1/2% of what number?
- Railway wagon
The railway wagon holds 75 m3 load. Wagon can carry a maximum weight of 30 tonnes. What is the maximum density that may have material with which we could fill this whole wagon? b) what amount of peat (density 350 kg/m3) can carry 15 wagons?
- Quadratic inequation
If 5x + x² > 100, then x is not
- Cube in sphere
The sphere is inscribed cube with edge 8 cm. Find the radius of the sphere.
- Trapezoid 15
Area of trapezoid is 266. What value is x if bases b1 is 2x-3, b2 is 2x+1 and height h is x+4
At 6 hours 40 minutes steamer sailed from the port at speed 12 km/h. At exactly 10 hours started sail motorboat at speed 42 km/h. When motorboat will catch steamer?
- Real estate
Residential house has three entrances numbered by odd numbers arithmetic progression. The sum of the two numbers on the corner entrances is 50. Calculate the highest of this three numbers.
- Isosceles right triangle
Contents of an isosceles right triangle is 18 dm2. Calculate the length of its base.
Draw a square ABCD whose diagonals have a length of 6 cm
- Concrete pedestal
The carpenters made wooden mold on a concrete pedestal in the shape of a cube with edge 2 meter long. What is the area in which the concrete touches wooden molds? (No lid or bottom)
Along the road were planted 250 trees of two types. Cherry for 60 CZK apiece and apple 50 CZK apiece. The entire plantation cost 12,800 CZK. How many was cherries and apples?
- MO Z6-6-1
Write integers greater than 1 to the blanks in the following figure, so that each darker box was product of the numbers in the neighboring lighter boxes. What number is in the middle box?
- Pizza 4
Marcus ate half pizza on monday night. He than ate one third of the remaining pizza on Tuesday. Which of the following expressions show how much pizza marcus ate in total?
- 3 children
3 children had to divide 4 pounds is candy. How much candy did each child get?
The park has 64 benches. Occupied are by 18 more than empty. How many benches are occupied and empty ?
- Isosceles triangle
Calculate area and perimeter of an isosceles triangle ABC with base AB if a = 6 cm, c = 7 cm.
If we increase the rhombus side by 2.4 cm; its perimeter is 20 cm. How long was the side of the rhombus?
Group of workers washing half of the windows of the building in two hours. How long will take half the workers wash all the windows of the building?