Math practice for 13 year olds - page 162 of 433
Number of problems found: 8660
- Distance 43431
On a map at a scale of 1:250,000, the line shows a distance of 15 km. How many cm does this line measure on the map?
- The roof
The tower's roof has the shape of a regular quadrangular pyramid, the base edge of which is 11 m long, and the side wall of the animal with the base at an angle of 57°. Calculate how much roofing we need to cover the entire roof if we count on 15% waste.
- The square
The square oak board (with density ρ = 700 kg/m3) has a side length of 50 cm and a thickness of 30 mm. 4 holes with a diameter of 40 mm are drilled into the board. What is the weight of the board?
- Previous 43371
The sum of three natural numbers, five greater than the previous one, is 204. What are the numbers?
- Who I
Who am I? My third is two less than my half.
- Altitude angle
In complete winds-free weather, the balloon took off and remained standing exactly above the place from which it took off. It is 250 meters away from us. How high did the balloon fly when we saw it at an altitude angle of 25°?
- Calculate 43331
From the lookout tower, 70 meters high, we see a man at a depth angle of 15 degrees. Calculate how far one stands from the base of the lookout tower. Draw and calculate.
- Inclination 43321
What percentage of the gradient should be indicated on the mark if the angle of inclination of the road is 6 ° 25'?
- Specified 43301
The water tank has the shape of a block. The bottom of the tank is square, with a side length of 3 m. There are 22,500 liters of water in the tank. To what height in meters does the water in the tank reach the specified amount?
- Cone-shaped 43291
Calculate the volume and weight of a pile of cone-shaped sand with a diameter of 8m and a height of v = 4.5m; the density of sand is 1500kg/M cubic.
- The aluminum
We placed the aluminum object with a weight of 0.80 kg and a temperature of 250°C in the water with a weight of 1.6 kg and a temperature of 23°C. What is the system temperature after reaching equilibrium? We assume that the heat exchange occurred only bet
- The bath
The bath has water with a volume of 220 l and a temperature of 65°C. Find the mass m2 of water at 15°C to be poured, so the resulting temperature in the bath will be 40°C. We neglect the heat exchange between water and the environment. Water's
- Calculate
Two friends Mário and Jano lived on two different sides of a highway. They decided to find out how wide it was. Mário drew a picture, based on which they then made measurements the next day. They measured the values a =5m, b= 5.9 m, and d = 5 m. Calcula
- An average a day
Forest workers planted 96 trees on Monday, 120 on Tuesday, and 61 on Wednesday. How many trees did she plant on the last day of Thursday if she planted an average of 105 trees a day?
- Calculation 43211
The roof is shaped like a hemisphere with a diameter of 8 m. Calculate how much m² of roofing is needed to cover the entire top if we count 15% for waste and residues and round the result to tenths of m². Use the constant pi rounded to two decimal places
- Diagonals of a prism
The base of the square prism is a rectangle with dimensions of 3 dm and 4 dm. The height of the prism is 1 m. Find out the angle between the body diagonal and the base's diagonal.
- Mr. Brown
Mr. Brown invested 15,000 euros in the bank for an annual term deposit. After the first year, he gained 600 euros. What was the annual interest rate of his deposit?
- The inflated
The inflated gymnastic ball should have a diameter of 65 cm. How many times do we have to pump air into a full-blown ball with a bicycle inflator to inflate it if the working volume of the inflator is a cylinder with an inner diameter of 2 cm and a height
- The granite ball
What is the weight of a granite ball with a radius of 60 cm if 1 m³ of granite weighs 2.7 tons?
- The vase
There were roses in the vase. Half were red, a quarter was white, and 12 were yellow. How many roses were in the vase?
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