Problem $1(40$ points$)$ Consider a line with two single$-$machine stations. Both machines take $=20$ mins and have $=1.$ Between the two machines there is a buffer that can hold $10$ jobs. $($a$)$ Model the system using an M$/$M$/1/$b queue. $($i$)$ What is the TH $($ii$)$ What is the WIP $($iii$)$ What is the CT for the line $($b$)$ Reduce the buffer to one and make the process time at the first machine to be $10$ mins. Re$-$ compute the above three measures.