Bunuel wrote:

The value of Brie’s heirloom pendant decreased by 50 percent from 2013 to 2015. What was the pendant’s value in 2013?

(1) The value of the pendant in 2014 was $3,000.

(2) The value of the pendant increased by 25% from 2015 to 2017, resulting in a value of $3,125 at the end of 2017.

(1) Value in 2014 = 3000, but no relation about 2013 or 2015. Not sufficient.

(2) So if value of pendant was 'x' in 2015, it increased by 25% making it 5/4 x and given that 5x/4 = 3125. This gives x = 2500

But this value must be 50% less than the value in 2013. So this value (2500) must be 1/2 of the value of 2013. This means value in 2013 = 2500*2 = $5000. Sufficient.

Hence

B answer