Astore pays $10 for a bracelet, and the markup is 115%

First find 115% of 10 then add it to 10.

115% × 10=
1.15×10 = $11.50

This is the markup

Now add it to the cost to get the marked up price

11.50 + 10 = $21.50

*note- you were not clear whether you wanted the amount of markup or the new marked up price.

Aand b is what i think