A mixture of the metals A and B where equivalent weights are 12 and 9 displace ${\text{H}}_{\text{2}}$ from an

acid. If 0.39 g of mixture displace 448 cc of hydrogen at STP. The mixture contains 

x × 11200 + y × 11200 = 448 CC

$\text{x\hspace{0.17em}+\hspace{0.17em}y\hspace{0.17em}=\hspace{0.17em}}\frac{448}{11200}\mathrm{.........}\left(1\right)$

x × 12 + y 9 = 0.39 gr

$4x+3y=\frac{0.39}{3}\mathrm{....}\left(2\right)$

From (1) and (2) x = 0.01, y = 0.09

$\therefore$ wt of element A = 0.01 × 12 = 0.12 gr

 wt of element B = 0.27gr