What is the 50th letter in this pattern: ABCAABBCCABCAABCC...
A
think about how many letters there are in a rep. i presume you can understand without an explanation. 50/9, then count the remainder.
wait a sec......
ABCAABBCC is not one rep,
look closely,
ABCAABBCCABCAABCC
one b and 2 b's