Gọi $n_{Al} = a(mol) ; n_{Fe} = b(mol) \Rightarrow 27a + 56b = 5,5(1)$
$2Al + 3H_2SO_4 \to Al_2(SO_4)_3 + 3H_2$
$Fe + H_2SO_4 \to FeSO_4 + H_2$
Theo PTHH : $n_{H_2} = 1,5a + b = \dfrac{4,48}{22,4} = 0,2(2)$
Từ (1)(2) suy ra : a = 0,1 ; b = 0,05
$\%m_{Al} = \dfrac{0,1.27}{5,5}.100\% = 49,1\%$
$\%m_{Fe} = 100\% - 49,1\% = 50,9\%$