S is the infinite sequence S1 = 2, S2 = 22, S3 = 222,...Sk = Sk–1 + 2(10k–1). If p is the sum of the first 30 terms of S, what is the eleventh digit of p, counting right to left from the units digit?
A) 1
B) 2
C) 4
D) 6
E) 9
what is easy way of solving this kind of problem...
A) 1
B) 2
C) 4
D) 6
E) 9
what is easy way of solving this kind of problem...