Question

quantos são os multiplos de 3  entre 1001 e 2001

Answer 1

$a1=1002\\ r=3\\ an=2001\\ \\ an=a1+(n-1)r\\ 2001=1002+(n-1)3\\ 2001-1002=3n-3\\ 999=3n-3\\ 999+3=3n\\ 1002=3n\\ \frac { 1002 }{ 3 } =n\\ \\ 334=n$