Prime numbers + multiplication - examples

  1. No. of divisors
    triangle_div How many different divisors has number ??
  2. Numbers
    ten Determine the number of all positive integers less than 2937474 if each is divisible by 11, 23, 17. What is its sum?
  3. Meadow
    ovce-miestami-baran On the meadow grazing horses, cows and sheep, together less than 200. If cows were 45 times more, horses 60 times more and sheep 35 times more than there are now, their numbers would equall. How many horses, cows and sheep are on the meadow together?
  4. LCM
    calc_icon What is the least common multiple of 28, 42, 22?
  5. Divisibility
    dots Determine the smallest integer which divided 8 gives remainder 6 when divided 19 gives remainder 9 and when divided by 11 gives remainder 2.
  6. Count of roots
    eggs How many solutions has equation x. y = 2531 with two unknowns on the set of natural numbers?
  7. Snowman 2
    snowman_1 On the medal, which has the shape of a circle with a diameter 17 cm is sketched snowman so that the following requirements are met: 1. snowman is composed of three circles, 2. space over snowman is the same as under it, 3. diameters of all circles express
  8. Racing track
    racing_track On the racing track circling three cars. The first passes one circuit for 8 seconds, the second for 16 seconds and a third for 15 seconds. a) Calculate number of seconds since the start to catch all three cars together for the first time again across the.
  9. Grandson and granddad
    vnuk_dedo Grandson with grandpa they counted how many years have together. Their product is 365. How many years is the sum of their years.
  10. Snowman
    snehuliak_1 In a circle with a diameter 41 cm are drawn 3 circles /as a snowman/ where: its diameters are integers, each larger circle diameter is 3 cm larger than the diameter of the previous circle. Determine snowman height if we wish highest snowman.
  11. Digits of age
    babka The product of the digits of Andrew age as 6 years ago and not equal to 0. Andrew age is also the smallest possible age with this two conditions. After how many years will be the product of the digits of Andrew age again the same as today?
  12. Lesson exercising
    atomium The lesson of physical education, pupils are first divided into three groups so that each has the same number. The they redistributed, but into six groups. And again, it was the same number of children in each group. Finally they divided into nine equal gr
  13. Four classses
    think Students of all 7, 8 and 9 classes in one school may take up 4,5,6 and 7 abreast and nobody will left. How many is the average count of pupils in one class if there are always four classes each grade?
  14. Two friends
    beers Two friends met as a good man perish together for a beer. After recovery the most important topics (politics, women, football ...), one asks: - And how many do you have children? - I have 3 children. - And how many years have? Friend already not want to an
  15. Lcm 2
    lcm Create the smallest possible number that is divisible by numbers 5,8,9,4,3
  16. Z7-I-4 stars 4949
    hviezdicky_mo Write instead of stars digits so the next write of product of the two numbers to be valid: ∗ ∗ ∗ · ∗ ∗ ∗ ∗ ∗ ∗ ∗ 4 9 4 9 ∗ ∗ ∗ ∗ ∗ ∗ 4 ∗ ∗
  17. MO Z6-6-1
    kruhy_1 Write integers greater than 1 to the blanks in the following figure, so that each darker box was product of the numbers in the neighboring lighter boxes. What number is in the middle box?

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