B$.$Operations Management Calculations

B$1)$Water Tech is a manufacturer of high$-$end electric toothbrushes. For each toothbrush, there is a sequence of assembly steps performed by five workers. Each worker does two tasks. Inventory buffers are allowed between workers.

$\backslash$table$[[$Worker Task,Time,$($seconds$)],[$A$,$T$1,40],[$A$,$T$2,25],[$B$,$T$3,20],[$B$,$T$4,15],[$C$,$T$5,10],[$C$,$T$6,15],[$D$,$T$7,10],[$D$,$T$8,20],[$E$,$T$9,25],[$E$,$T$10,35]]$

$($a$)$ What is the capacity of this process $($toothbrushes per minute$)?$