(a) By removing one or more of the twelve clock vectors, make…

(a) By removing one or more of the twelve clock vectors, make the length $|\mathbf{V}|$ as large as possible.
(b) Suppose the vectors start from the top instead of the center (the origin is moved to 12 o'clock, so ${\mathbf{v}}_{12}=0$). What is the new sum ${\mathbf{V}}^{\ast }$?

Gilbert Strang, Calculus, 3rd edition (Wellesley-Cambridge Press; MIT OpenCourseWare RES.18-001) · §11.1 Vectors and Dot Products, #14