*̶*̶*̶g̶i̶v̶e̶a̶w̶a̶y̶*̶*̶*̶ ̶f̶r̶e̶e̶ ̶9̶9 ̶p̶t̶s̶ ̶f̶o̶r̶ ̶t̶h̶i̶s̶ ̶q̶u̶e̶s̶t̶i̶o̶n
-why do earthquakes commonly happen at plate boundaries?

Aproduction line at v. j. sugumaran's machine shop has three stations. the first station can process a unit in 7 minutes. the second station has two identical machines, each of which can process a unit in 16 minutes (each unit only needs to be processed on one of the two machines). the third station can process a unit in 10 minutes. ▼ is the bottleneck station, with a bottleneck time of nothing minutes per unit (enter your response as a whole number).