Factors produce numbers. To get 840, use these factor pairs: (840,1)(420,2)(280,3)(210,4)(168,5)(140,6)(120,7)(105,8)(84,10)(70,12)(60,14)(56,15)(42,20)(40,21)(35,24)(30,28)
Multiples are numbers that a number (840 in this case) is a factor of.Multiples of 840: 1680, 2520, 3360, and so on.
840
All multiples of 840 are common multiples of 60 and 280
They are: 3*5*7*8 = 840, except they are factors.
840
That's an infinite list.
Any multiple of 42000
Any multiple of 4200
Any multiple of 840.
840, 1680, 2520 and so on.
420, 840, 1260 and so on.
280, 560, 840 and so on.