81. $HCF \times LCM = Product$
82. Number with exactly 2 factors
83. Number with > 2 factors
84. 15
85. $\sqrt{2}, \sqrt{8}$
86. $2^2 \times 5^2$
87. 1
88. $xy$
89. Yes
90. Yes (0/1)
91. Denominator in $2^n 5^m$ form
92. 10
93. 20
94. 2
95. 3
96. Euclid
97. Rational
98. $3/8$
99. $2^2 \times 5 \times 7$
100. No