Since we know that a number is divisible by 3 if the sum of all digits is divisible by 3.
Let us check which digits will make 371? divisible by 3.
[tex]3+7+1+0=11[/tex]
11 is not divisible by 3.
Now let us check other digits as well.
[tex]3+7+1+1=12[/tex]
12 is divisible by 3.
[tex]3+7+1+4=15[/tex]
15 is also divisible by 3.
[tex]3+7+1+7=18[/tex]
18 is divisible by 3 as well.
Therefore, 1, 4 and 7 in tenth place will make our number divisible by 3 and our numbers will be 3711, 3714 and 3717.
