apple100 wrote:what is the general approach to remainder questions?

This question is somewhat similar to the popular question "How long is a piece of string?"

Nevertheless, two approaches that come to mind are:
1) Know how to create the dividend given information about quotients, remainders, etc.
Example: if 17 divided by 5 is 3 with a remainder of 2, then 5x3+2 = 17
In general, if a divided by b is c with a remainder of d, then bxc+d = a

2) Listing possible values often provides some insight to a question.
Example, if we are told that when positive integer x is divided by 6, the remainder is 1, then some possible values for x include 1, 7, 13, 19, 25, etc
(note: when 1 is divided by 6, the quotient is 0 and the remainder is 1)