We declared a two dimensional array SampleArr as follows in $C++$ :

float SampleArr$[15][6]$;

a$)$ Assume the start memory address of this array is $500$ and a float element occupies a $4$ bytes memory space. The array is stored in row major order. Calculate the memory address for the element SampleArr$[8][5].$

b$)$ Draw the compiler$-$time descriptor for the array SampleArr.