Math practice for 13 year olds - page 242 of 425
Number of problems found: 8489
- Reading records
Lucy, Tereza, and Petra decided to compile the compulsory reading records together. It would take 30 days for Lucia alone, 36 for Tereza, and 45 for Petra. How long will it take to make records if they will work together?
- The difference
The difference between the two numbers is 1375. If their exact quotient is 12. Find the two numbers
- Iron pole
The iron pole is in the ground 2/5 of its length, partly above the ground 1/3 is yellow, and the unpainted section is 6 m long. How long is the entire column?
- Cook on gas
The gas cylinder will last 30 weekends for 2 hours of daily cooking. How many days will we be able to cook on a new cylinder when we cook for 3 hours a day?
- Competition 8193
David caught three carp races. The second was 15 cm longer than the first. The third is 8 cm shorter than the second. David entered a total length of 166 cm in the competition. How big a carp did he catch?
- Diagonal 8192
Find the volume and surface of a cube if you know the length of its body diagonal u = 216 cm.
- Accommodated 8189
One hundred sixty-nine pupils were accommodated in 45 rooms at the outdoor school. Some were triple, and some quadruple, and all were fully occupied. How many were triple and quadruple rooms there?
- Vertebrate 8181
Cyclists drove the first half of the track at an average of 37.5 km/h in 1.4 hours. After the vertebrate, they walked the same distance 6 minutes longer. At what average speed did they drive on the vertebrate?
- Cross-section - digging
How many m³ of soil is to be excavated when digging a 120 m long ditch, the cross-section of which is an isosceles trapezoid with bases of 2.3 m and 3.3 m, if the depth of the trench is 90 cm?
- Hexagon 8167
How many dm² of organic glass is needed to produce 50 washers in the shape of a regular hexagon? The side is 8 cm long.
- Calculate 8166
Calculate the perimeter of a square when we know the length of its diagonal e = 4.2 m
- Four pavers
Four pavers would pave the square in 18 days. How many pavers do you need to add to the done work in 12 days?
- Three gardens
Is it possible to divide a plot of land with an area of 927 m² into three gardens in a ratio of 4:2:3 so that their areas are only whole multiples of square meters?
- Thought 8153
When I add half of the thought number to 3/5 of the thought number, I get the sum of 22. Which number do I think?
- Shopping center
The shopping center buys bikes from the manufacturer for 180 €. It sells them for a sale price of 250 €. However, in the advertising for the sale of these goods, the shopping center spent 20% of the selling price of all bicycles in stock. How many bikes d
- Expression 8150
Find for which x the value of the expression 13x - 7 is eight less than the value of the expression. 12x + 11.
- Previous 8148
The sum of three natural numbers is 204. Each of them is five greater than the previous one. What are the numbers?
- Pillar 8147
The height of the column is 75 cm and still half its height. How tall is the pillar?
- Dentist
Class 5. I participated in a preventive dental examination. A quarter of the pupils found two dental caries, and an eighth found one caries. Half the class had all their teeth healthy. How many students attend class 5? If four students were missing on the
- Hundred-euro 8140
Mr. Novák had one hundred and fifty euro bills in his wallet. There were 21 in total, and their total value was 1550 euros. How many hundred-euro and how many fifty-euro notes did Mr. Novák have in his wallet?
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