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.

Final Answer:

x = 6,15,21,70

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



Help us improve! If you spot a mistake, please let let us know. Thank you!







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

You need to know the following knowledge to solve this word math problem:

Related math problems and questions: