Swarna paid Rs 20 as VAT on a pair of shoes worth Rs 250.

Given,

Amount paid by Swarna for a pair of shoes $=R s .250$

VAT paid by her $=$ Rs. 20

Let the rate of VAT be $x \%$

Then,

$x \%$ of $250=20$

$\frac{x}{100} \times 250=20$

$2.5 x=20$

$x=8$

Thus, Swarna paid $8 \%$ VAT on the pair of shoes.