Sunita purchases a bicycle for Rs 660. She has paid a VAT of 10%.

Let the sale price of the bicycle be Rs. $x$.

VAT charged $=10 \%$

Again,

Cost of the bicycle $=x+10 \%$ of $x$

$660=x+0.10 x$

$660=1.10 x$

$x=\frac{660}{1.10}$

$x=R s .600$

Thus, the list price of the bicycle is Rs. 600 .