Solution: Equipment Depreciation Tracker

double calculateDepreciation(double initialValue, int years) {
  
  double applyDepreciation(double currentValue, int yearsLeft) {
    if (yearsLeft <= 0) {
      return currentValue;
    } else {
      return applyDepreciation(currentValue * 0.90, yearsLeft - 1);
    }
  }
  
  return applyDepreciation(initialValue, years);
}
void main() {
  double truckValue = 50000.0;
  int yearsUsed = 3;
  double currentValue = calculateDepreciation(truckValue, yearsUsed);
  print(currentValue);
}