Question $19(1$ point$)$

The total$-$cost curve in queuing theory is not $U-$shaped; it can have various shapes depending on the specific scenario.

True

False

Question $20(1$ point$)$

For an infinite$-$source model, it's always necessary to use a trial$-$and$-$error approach to determine the optimum number of servers; analytical methods can't be used.

True

False

Question $21(1$ point$)$

Queuing theory encompasses various models, including single$-$channel, multiplechannel, multiple$-$priority, and finite$-$source models.

True

False