Suppose $A[1],A[2],A[3],$dots,$A[n]$ is a one$-$dimensional array and $n>50.$

$($a$)$ How many elements are in the array?

$($b$)$ How many elements are in the following subarray?

$A[4],A[5],$dots,$A[37]$

$($c$)$ If $3mn,$ what is the probability that a randomly chosen array element is in the following subarray?

$A[3],A[4],$dots,$A[m]$

$($d$)$ What is the probability that a randomly chosen array element is in the subarray shown below if $n=57?$

$A[{|}_{{?}_{?}}\frac{n}{2_{{?}_{?}}}|],A[{|}_{{?}_{?}}\frac{n}{2_{{?}_{?}}}|+1],$dots,$A[n]$