MO C–I–1 2018

An unknown number is divisible by just four numbers from the set {6, 15, 20, 21, 70}. Determine which ones.

Result

x = (Correct answer is: 6,15,21,70) Wrong answer

Step-by-step explanation:

6=23 15=35 20=225 21=37 70=257 LCM(6,15,20,21,70)=22357=420  a=LCM(6,15,20,21,70)=420  x1=210 x2=630 x3=1050 x4=1470 x5=1890 x6=2310 x7=2730   d(210)=1,2,3,5,6,7,10,14,15,21,30,35,42,70, d(630)=1,2,3,5,6,7,9,10,14,15,18,21,30,35,42,45,63,70,  LCM(6,15,21,70)=2357=210  k=LCM(6,15,21,70)=210  x=6,15,21,70



Did you find an error or inaccuracy? Feel free to write us. Thank you!






avatar




Tips to related online calculators
Do you want to calculate least common multiple two or more numbers?
Do you want to calculate greatest common divisor two or more numbers?

Related math problems and questions:

  • Coloured numbers
    olympics Mussel wrote four different natural numbers with coloured markers: red, blue, green and yellow. When the red number divides by blue, it gets the green number as an incomplete proportion, and yellow represents the remainder after this division. When it div
  • Apples and pears
    hrusky2 Mom divided 24 apples and 15 pears to children. Each child received the same number of apples and pears - same number as his siblings. How many apples (j=?) and pears (h=?) received each child?
  • Lcm of three numbers
    prime What is the Lcm of 120 15 and 5
  • Decompose
    cinema Decompose into primes and find the smallest common multiple n of (16,20) and the largest common divisor D of the pair of numbers (140,100)
  • Pyramid Z8–I–6
    pyramida_mo Each brick of pyramid contains one number. Whenever possible, the number in each brick is lowest common multiple of two numbers of bricks lying directly above it. That number may be in the lowest brick? Determine all possibilities.
  • LCD 2
    zlomky The least common denominator of 2/5, 1/2, and 3/4
  • Trees in alley
    tree There are four trees in the alley between which the distances are 35m, 15m and 95m. Trees must be laid in the spaces so that the distance is the same and the maximum. How many trees will they put in and what will be the distance between them?
  • Year 2018
    new_year The product of the three positive numbers is 2018. What are the numbers?
  • Length of a string
    meter What is the smallest length of a string that we can cut into 18 equal parts and even 27 equal parts (in decimeters)?
  • Counting number
    numbers2 What is the smallest counting number divisible by 2,5,7,8 and 15?
  • Reminder and quotient
    prime There are given the number C = 281, D = 201. Find the highest natural number S so that the C:S, D:S are with the remainder of 1,
  • Paving - joints
    tiles We are paving with rectangular pavement 18 cm × 24 cm was placed side by side in height in a row and in the second row in width etc. How many times will the joints meet at a distance 10 m?
  • 9.A
    exam 9.A to attend more than 20 students but fewer than 40 students. A third of the pupils wrote a math test to mark 1, the sixth to mark 2, the ninth to mark 3. No one gets mark 4. How many students of class 9.A wrote a test to mark 5?
  • Lcm 2
    lcm Create the smallest possible number that is divisible by numbers 5,8,9,4,3
  • The tickets
    oriesky The tickets to the show cost some integer number greater than 1. Also, the sum of the price of the children's and adult tickets, as well as their product, was the power of the prime number. Find all possible ticket prices.
  • Two buses
    bus27 The first bus runs 15 minutes the second bus runs after 21 minutes. Together they both leave at 7:00 on Monday. When and what day will they meet?
  • Blades
    ruler2 1st blade 2,5 m, 2nd blade. .1.75 m. How many same long pieces of this two blades can be do the biggest? How long is one piece?