Zn(OH)2
Zinc has a molar mass of 65.38 g/mol
Oxygen has a molar mass of 16.00 g/mol
Hydrogen has a molar mass of 1.01 g/mol

Therefore, the molar mass of Zn(OH)2 = 65.38 + 2(1.01) + 2(16.00) = 99.40 g/mol

Al2(SO4)3
Aluminum has a molar mass of 26.98 g/mol
Sulfur has a molar mass of 32.06 g/mol
Oxygen has a molar mass of 16.00 g/mol

Therefore, the molar mass of Al2(SO4)3 = 2(26.98) + 3(32.06) + 12(16.00) = 342.12 g/mol

CaCO3
Calcium has a molar mass of 40.08 g/mol
Carbon has a molar mass of 12.01 g/mol
Oxygen has a molar mass of 16.00 g/mol

Therefore, the molar mass of CaCO3 = 40.08 + 12.01 + 3(16.00) = 100.09 g/mol

Therefore, the Mr (molar mass) of Zn(OH)2 is 99.40 g/mol, of Al2(SO4)3is 342.12 g/mol, and of CaCO3 is 100.09 g/mol.