Math practice for 13 year olds - page 315 of 423

Number of problems found: 8460

Double ladder
The double ladder shoulders should be 3 meters long. If the lower ends are 1.8 meters apart, what height will the upper top of the ladder reach?
Calculation 4718
The bank has a total of CZK 1,390 in 50 banknotes. How many banknotes are worth CZK 20 and CZK 50? Please follow the calculation procedure. Thank you
Billboard
A rectangular billboard is 2.5 m long with a diagonal of 2.8 m long. Calculate the perimeter and the area of the billboard.
Isosceles triangle
Calculate the area and perimeter of an isosceles triangle ABC with base AB if a = 6 cm, c = 7 cm.
Rhombus sides
If you decrease the side of the rhombus by 30 mm, its circumference will be 70.8 mm. How long was the side of the original rhombus?
Rhombus
If we increase the rhombus side by 2.4 cm, its perimeter is 20 cm. How long was the side of the rhombus?
Land - isosceles trapezoid
Calculate the building plot's area and perimeter using an isosceles trapezoid with bases of 120m and 95 m and a height of 50m.
Empty canister
The canister is filled with oil and weighs 17 kg. Suppose only half is filled, weighing 9 kg. What weight does my empty canister have?
Square
Calculate the square's perimeter and area with a diagonal length of 30 cm.
Influenza 4707
There were 36 new cases of influenza at the school during the study week, which was 40 percent less than in the previous week. How many new flu cases have been reported in the last week?
Toy cars
Paul has a collection of toy cars. He wanted to regroup them. But when he divided them into groups of three, four, six, and eight, he was always one left. Only when he formed groups of seven did he divide all toy cars. How many toy cars are in the collect
Dimensions 4700
The toolbox has internal dimensions, a length of 1.5 meters, a width of 80 cm, and a height of 6 dm. Calculate the longest rod we can hide in this box.
Two aircraft
From the airport will start simultaneously two planes, whose flight tracks are perpendicular to each other. The first flying speed of 680 km/h and the second 840 km/h. Calculate how far the aircraft will fly for half an hour.
Three-digit code
The five cards with the numbers 1, 2, 3, 4, and 5 put together all three-digit odd numbers. How many are there?
Diagonals of diamond
Find the area and circumference of the diamond ABCD with 15m and 11m diagonals.
Diamond 4695
The handle is made of alloy. The alloy is in a ratio of 6 parts gold, three parts lead, and eight parts diamond. The handle weighs 24 kg. How much weight are gold and lead?
Cube diagonal
Calculate the length of the body diagonal in a cube of 15 cm.
Workers
A Group of workers washed half of the windows of the building in two hours. How long will it take half the workers to wash all the windows of the building?
Circular 4690
The cone shell with a base radius of 20 cm and a height of 50 cm unfolds into a circular cutout. How big is the center angle of this cutout?
Calculate 4689
The area of the rotating cone shell is 240 cm², and the area of its base is 160 cm². Calculate the volume of this cone.

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