when 247 is divided by 6,
41
6)247
24
7
6
1
the remainder is r,
I got a remander of 1, so r is 1
and when 247 is divided by 12,
20
12)247
24
7
0
7
the remainder is s.
I got a remainder of 7, so s is 7
what is the value of r – s ?
Since r is 1, and s is 7, then r - s = 1 - 7 = -6
So the answer is -6, which is choice (a)
Edwin