Two sabassemblies, A and B$,$ are prosessed iparately, each requining mo finishing operatioes, B i reeted through operations $1$ and $2,$ and A is routed through operations $3$ and $4.$ The two subassamblies are then jolned it an assembly operation $($operation $5).$ The five operations have the following fraction defect rates: gr$-0\mathrm{.}04,9$r$-005,$ Qr$-0\mathrm{.}08,$ ge$-0\mathrm{.}09,$ gu$-0\mathrm{.}03.1/$ the desired final quantity of completed assemblies is $12,000$ units, how many starting waits of Aard B will be required? Thire is no inspection oe repuration of defective units until after the final operation, so defective waiti and good wniti are processed together through all processing and assembly steps.