a$)$ Convert the number $0$x$40$b$80000($hex$)$ from single$-$precision floating$-$point representation to decimal.

b$)$ How is the number $-18\mathrm{.}0$ represented in single precision floating point notation? Present only the $12$ most significant bits of the answer.

c$)$ Assuming an $8-$bit word, considering the integer representation in two's complement, how is the number $-117$ represented?