55. Samantha had 75 necklaces to sell.
For the first week, there was only 57 necklace left
=> 75 – 57 = 18
Thus, 18 necklace were sold. Let’s solve for the percentage
=> 18 / 75 = 0.24
=> 0.24 * 100 = 24%
Thus for the first week she were able to sell 24% of the necklace.
For the second week, there was only 38 necklace left.
Now the remaining from first week is 57.
=> 57 – 38 = 19
=> 19 / 57 = 0.33
=> 0.33 * 100 = 33%
Thus on the second week it decreased around 33%.