$\frac{12/5\times {{10}^{-14}}}{25\times {{10}^{-19}}}=\frac{125\times {{10}^{-1}}\times {{10}^{-14}}}{25\times {{10}^{-19}}}=5\times {{10}^{-15}}\times {{10}^{19}}=5\times {{10}^{4}}$