Prime numbers - 7th grade (12y) - math problems

Number of problems found: 145

  • The classroom
    meter The classroom is 9 meters long. The width of the classroom is smaller and can be passed in equally long steps of 55 CM or 70 CM. Determine the width of the classroom.
  • Square gardens
    zahrada The gardening colony with dimensions of 180 m and 300 m is to be completely divided into equally large square areas with the largest possible area. Calculate how many such square areas can be obtained and determine the side length of the square.
  • Summer camp
    tablo Some boys or girls signed up for the summer camp, which has a maximum capacity of 200 children. The main leader noticed that during the evening start, he could arrange the participants exactly in the twelve-step, sixteen-step, or eighteen-step, and no one
  • Tractor wheels
    tractor The front wheel of the tractor has a circumference of 18 dm and the rear 60 dm. We will make a red mark on the lowest point of both wheels. The tractor then starts. At what distance from the start will both marks appear identically at the bottom again?
  • Three
    bus27 Three buses follow the same circular route. The first driver is the slowest because he has many stops, and it takes him 90 minutes to cross the route. The second driver will pass the circuit in 1 hour. The third driver has the fewest stops, and the circui
  • Pegs
    meter From two sticks 240 cm and 210 cm long, it is necessary to cut the longest possible pegs for flowers so that no residues remain. How many pegs will it be?
  • Divisible by nine
    numbers How many three-digit natural numbers in total are divisible without a remainder by the number 9?
  • Two gears
    gears-3 Two gears with 13 and 7 teeth rotate locked into each other. How many turns does a big wheel have to make for both wheels to be in the starting position again?
  • Three ships
    ship There are three ships moored in the port, which sail together. The first ship returns after two weeks, the second after four weeks, and the third after eight weeks. In how many weeks the ships will meet in the port for the first time? How many times have
  • Ratio
    maliny Alena collected 7.8 kg of blueberries, 2.6 kg of blackberries, and 3.9 kg of cranberries. Express the ratio in the smallest natural numbers in this order.
  • On a
    venusa On a some day, the Sun, Venus and the Earth are in eclipse, i. E. Venus is between the Sun and the Earth. Venus orbits the Sun in 225 days. In how many years will all three bodies be in alignment again?
  • Drivers
    clocks2 Driver Franta and driver Karel are friends. They leave the start-stop both at the same time in the afternoon - at 13.30. When will they meet again if Franta goes around his route in 50 minutes and Karel in 40 minutes?
  • Tram stop
    elektricka The blue tram stops every 12 minutes, the red one 8 minutes. At 8 o'clock they left the stop together. How many times do they meet at a stop before 11 am?
  • Identical cubes
    cubes3 From the smallest number of identical cubes whose edge length is expressed by a natural number, can we build a block with dimensions 12dm x 16dm x 20dm?
  • Largest squares
    metals How many of the largest square sheets did the plumber cut the honeycomb from 16 dm and 96 dm?
  • The florist
    ruze A consignment of 200 roses arrived at the florist in the morning. She sold more than half of them during the day. She wants to tie bouquets of the remaining roses. If she ties a bouquet of three, four, five, or six roses, there will always be one rose lef
  • An example
    cubes3 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: A cuboid was made from a block of 16x18x48 mm of modeline. What will be the edge of t
  • Twenty-five
    prime How many are three-digit natural numbers divisible by 25?
  • Quotient
    math Find quotient before the bracket - the largest divisor 51 a + 34 b + 68 121y-99z-33
  • Rectangles
    rectangles How many different rectangles can be made from 60 square tiles of 1 m square? Find the dimensions of these rectangles.

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Prime numbers - math problems. Examples for 7th grade (seventh).