Answer:
we must first determine the annual payment:
annual payment = present value / annuity factor
present value = $25,000
PV annuity factor, 10%, 3 periods = 2.4869
annual payment = $25,000 / 2.48685 = $10,052.87
year       payment     interest paid       principal paid       ending balance
1          $10,052.87      $2,500              $7,552.87             $17,447.13
2         $10,052.87      $1,744.71           $8,308.16              $9,138.97
3         $10,052.87      $913.90             $9,138.97              $0
in percentages:
year       payment     interest paid       principal paid     
1               100%            25%                        75% 
2              100%        17.36%                   82.64%
3              100%         9.09%                   90.91%