AHSME 1968 Problem 20

The measures of the interior angles of a convex polygon of $n$ sides are in arithmetic progression. If the common difference is $5^{\circ}$ and the largest angle is $160^{\circ}$, then $n$ equals: $\text{(A) } 9 \text{(B) } 10 \text{(C) } 12 \text{(D) } 16 \text{(E) } 32$