Since 100, 99 & 98 have no sevens we can limit our search to 1 - 97. There will be ten 7's in the ones column and one 7 in the tens column. So it looks like eleven 7's is the answer.
5.28751 7s equals 37.
5
14
18
80.
6
answer:4
10
6
4
There are normally two.
5