$($Problem $1\mathrm{.}30$ Points$)$ You are designing a simple memory addressing system for a digital device. The device uses $16-$bit binary memory addresses. Convert the following hexadecimal memory addresses to their equivalent $16$ bit binary addresses:

a$)$ ZA$7$F $($hexadecimal$)$

b$)$ FF$00($hexadecimal$)$

c$)1234($hexadecimal$)$