Discounted price should be taken away from the marked price.

Think of formula of simple interest.

Think of formula of profit. Selling price should be more than cost price.

Convert both inÂ fractionÂ or in percentage.

Is it loss or profit? Find difference of money she paid and she got.

Increased means making bigger and we need to add.

Find the total number of rings.

Find the total number of rings.

Decrease means getting smaller.

Subtract discount from marked price.