ok
 75 ----------------------- 12
 100 ----------------------- x
 x = (100 x 12) / 75
 x = 1200 / 75
 x = 16
In total there were 16 pies.
12 pies were sold out and 4 (16 - 12) were thrown away.
The answer is 4 pies
2) 8000 ------------------------- 100%
 x ------------------------- 16%
 x = (16 x 8000) / 100
 x = 128000/100
 x = 1280
It sold 1280 tickets as reserved