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

  1. An example
    cubes3_2 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
  2. Profitable company
    penize Three businessman decide to open up their own company. They agree to distribute the yearly profits made in the same ratio as their initial investments. They invest R 50 000, R 75 000 and R25 000, respectively. The profit made by the company in the first y
  3. Twenty-five
    prime How many three-digit natural numbers are divisible by 25?
  4. Quotient
    math Find quotient before the bracket - the largest divisor 51 a + 34 b + 68 121y-99z-33
  5. Rectangles
    rectangles_1 How many different rectangles can be made from 60 square tiles of 1 m square? Find the dimensions of these rectangles.
  6. Three lines
    clocks2 At 6 am, three bus lines are departing from the station. The first line has an interval of 24 minutes. The second line has an interval of 15 minutes. The third line runs at regular intervals of more than 1 minute. The third line runs at the same time as t
  7. Common divisors
    prime Find all common divisors of numbers 30 and 45.
  8. Number
    prime What number should be placed instead of the asterisk in number 702*8 to get a number divisible by 6?
  9. Dance group
    dancers The dance group formed groups of 4, 5, and 6 members. Always one dancer remains. How many dancers were there in the whole group?
  10. The King
    gold_4 The King wants to divide his sons equally. He has 42 rubies and 45 diamonds. How many sons and how will they share them?
  11. Reminder and quotient
    prime_4 There are given numbers A = 135, B = 315. Find the smallest natural number R greater than 1 so that the proportions R:A, R:B are with the remainder 1.
  12. The florist
    ruze_6 The florist had 200 roses in the morning. During the day, more than half sold it. From the remaining roses, it will tie the bouquet. If a bouquet of 3, 4, 5 or 6 roses are bound, one always remains. How many roses from the morning shipment sold?
  13. Container
    cubes3_9 The container-shaped box with internal dimensions of 3.9 m, 3.25 m and 2.6 m was completely filled with goods in the same cubic boxes. How long edge could this box have?
  14. Counting number
    numbers2_49 What is the smallest counting number divisible by 2,5,7,8 and 15?
  15. 7 digit number
    numbers2_49 If 3c54d10 is divisible by 330, what is the sum of c and d?
  16. Prime factors
    prime Write 98 as product of prime factors
  17. Two rectangles
    rectangles2_2 I cut out two rectangles with 54 cm², 90 cm². Their sides are expressed in whole centimeters. If I put these rectangles together I get a rectangle with an area of 144 cm2. What dimensions can this large rectangle have? Write all options. Explain your calc
  18. Three friends
    gulky_9 Three friends had balls in ratio 2: 7: 4 at the start of the game. Could they have the same number of balls at the end of the game? Write 0, if not, or write the minimum number of balls they had together.
  19. School
    ziaci_6 Less than 500 pupils attend school. When it is sorted into pairs, one pupil remains. Similarly, when sorted into 3, 4, 5 and 6 members team one remains. Sorted to seven members teams, no left behind. How many pupils are attending this school?
  20. Glass panel
    glass_4 A rectangular glass panel with dimensions of 72 cm and 96 cm will cut the glazier on the largest square possible. What is the length of the side of each square? How many squares does the glazier cut?

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