SOLUTION :
Rs. $140=100 \%$ of Cost Price
$\therefore \quad$ Re. $1=\frac{100}{140} \%$ of the Cost Price
$\therefore \quad$ Rs. $133=\frac{100}{140} \times 133 \%$ $=95 \%$ of the Cost Price
$\therefore$ The required loss percent $=100-95=5 \% ;$ Ans.