The answer is same.
Finding the percentage of change for Troop A :
New - Original / Original × 100%
- 16 - 14 / 14 × 100%
- 1/7 × 100%
- 14.29%
Finding the percentage of change for Troop B :
- 24 - 21 / 21 × 100%
- 1/7 × 100%
- 14.29%
Both the troops have the same percent change in membership.