It has to be 14.
If you ended up with a remainder of 15 or higher then you wouldn't have done your division correctly!
As a whole number it is 14
645 divide by 43 in steps no remainder = 15
15
28.3333
The remainder is 3 5 x 3 = 15 18 - 15 = 3
5
15 divided by 7 = 2 R1 (Two remainder one) As a decimal, it is 2.14285714
15 ÷ 2 = 7 with remainder of 1, and 15 ÷ 7 = 2 with remainder of 1, if that's what you are looking for.
1.25
1 and 5.
3 with a remainder of 15 or 3.4286
15