# If you were to produce a 3 digit multiple of 7 that has a final digital sum of 7 using the formula; 7(1+9k). How do you calculate what k is?

##### 1 Answer

May 16, 2015

If I understand the question correctly, we get several constraints from the conditions:

Dividing all parts by 7 we get

Subtracting 1 from all parts we get

Dividing all parts by 9 we get

So

All of these values of