AHSME 1969 Problem 33

Let $S_n$ and $T_n$ be the respective sums of the first $n$ terms of two arithmetic series. If $S_n:T_n=(7n+1):(4n+27)$ for all $n$, the ratio of the eleventh term of the first series to the eleventh term of the second series is: $\text{(A) } 4:3 \text{(B) } 3:2 \text{(C) } 7:4 \text{(D) } 78:71 \text{(E) undetermined}$