Maths practice for 12-year-olds - page 188 of 351

Number of problems found: 7018

Harvester calculation time
During the harvest, farmers had three combine harvesters available, with which they could harvest the fields in 9 hours. How long will it take if two additional harvesters arrive from a neighbouring farm to help?
Jana height calculation
Jana measures 4/5 of Dad's height. Mom measures 160cm, which is 1/4 less than Dad. What is Jan's height?
Water tank calculation
The water tank has the shape of a block. The inner length is 5.2 meters, the width is 2.4 meters, and the depth is 1.5 meters. If the tank is filled to 3/5 of its depth, how many liters of water does it contain?
Pump water tank
The pressure pump delivers two cubic meters of water to the block-shaped water tank in 1 minute. The tank has a 7 m and a width of 5 meters. How much water does it draw in 1 hour? How high does the water reach in the tank?
Cuboid walls
The block's base is a rectangle whose sides have lengths in the ratio of 13:7. Find the volume of the block in liters if the longer side of the base measures 65 cm and the height of the block is 1.2 m
Tank filling time
The pump delivers 34 hl of water per minute. How long does it take to fill the tank with a volume of 10m³? Write the result in hours and minutes.
Tank solution fitting
Will 600 liters of solution fit in a cuboid-shaped tank with bottom dimensions of 2.5m and 1m and a height of 3dm?
Resistor voltage calculation
The resistor has a value of 50 ohms, and a current of 120 mA passes through it. What is the voltage across the resistor?
Channel cross-section area
Calculate the cross-sectional area of the trapezoidal channel irrigation channel if its upper width is 7.9 m, its bottom width is 5.5 m, and its depth is 2.8 m.
Sticker paper calculation
The sticker is shaped like a triangle with a side 5.4 cm long and 3 cm high. Most of such stickers can be made of 1 m² paper.
A lot of hay
Martin's grandfather weighed a lot of hay and calculated that it would last 100 days for 15 rabbits. How many days will this lot be enough for 25 rabbits?
Snack
The teacher paid CZK 450 for a snack for 30 pupils. How many CZK will we pay for the same snack for 28 pupils?
Granite cube buoyancy
The granite cube with an edge length of 1 dm and a weight of 2.5 kg is immersed in a container with water. How much buoyancy makes it lighter? How much compressive force does the cube exert on the bottom of the container?
Rectangle area comparison
The rectangle has 10 and 8 cm dimensions on a 1:10 scale plan. How many times does it have more area than on the plan?
Corridor plastering time
According to the standard, we calculated that two masons would plaster the corridor of the new school building in 54 hours. How long would it take for nine bricklayers to plaster this corridor?
Coal supply duration
With the consumption of 0.4 t of coal per day, the supply lasts for 36 days. How many days will the supply be enough if 16 kg of coal is used less daily?
Apple drying calculation
Last year, Mirek's aunt dried 4.8 kg of fallen apples from 30 kilograms of fallen apples. He wants to dry the crosses from 50 kilograms of apples this year. Approximately how many kg will he gain?
An example
An example is playfully for grade 6 from Math, and I don't know how to explain it to my daughter when I don't want to use the calculator to calculate the cube root. Thus: The student made a cuboid from a block of 16x18x48 mm of plasticine. What will be th
Harvester wheat calculation
A field of wheat can be harvested by 7 combine harvesters in 5 days at full capacity. The weather forecast called for the harvest to be completed in 4 days. How many combines were needed in total?
Class girl calculation
One-fifth of the girls are honored in the class, and the remaining eight girls are doing well. How many girls are in the class?

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