Answer
a) 9
b) 4
c) 25
d) 0
Work Step by Step
a) $(99^2\quad mod\quad 32)^3 \quad mod\quad 15$ = 9
b) $(3^4 \quad mod\quad 17)^2 \quad mod\quad 11$ = 4
c) $(19^3\quad mod\quad 23)^2 \quad mod\quad 31$ = 25
d) $(89^3\quad mod\quad 79)^4 \quad mod\quad 26$ = 0
