A processor has $$40$$ distinct instructions and $$24$$ general purpose registers. A $$32$$-bit instruction word has an opcode, two register operands and an immediate operand. The number of bits available for the immediate operand field is __________ .

Suppose the functions $$F$$ and $$G$$ can be computed in $$5$$ and $$3$$ nanoseconds by functional units $${U_F}$$ and $${U_G},$$ respectively. Given two instances of $${U_F}$$ and two instances of $${U_G},$$ it is required to implement the computation $$F\left( {G\left( {{X_i}} \right)} \right)$$ for $$1 \le i \le 10.$$ Ignoring all other delays, the minimum time required to complete this computation is _____________ nanoseconds.

The width of the physical address on a machine is $$40$$ bits. The width of the tag field in a $$512$$ $$KB$$ $$8$$-way set associative cache is _____________ bits.

Breadth First Search $$(BFS)$$ is started on a binary tree beginning from the root vertex. There is a vertex $$t$$ at a distance four from the root. If t is the $$n$$-th vertex in this $$BFS$$ traversal, then the maximum possible value of $$n$$ is ___________.