Tanya originally bought 6 pears + 4 Granny Smith apples + 2 pineapples + x plums = 12 + x total pieces of fruit.
She lost half of the fruit, so she lost (1/2)(12 + x) = 6 + (1/2)x pieces of fruit.
After losing half the fruit, she is left with 9 pieces, so 6 + (1/2)x = 9.
Subtracting 6 from both sides gives (1/2)x = 3.
Multiplying both sides by 2 gives x = 6.
Therefore, Tanya originally purchased 6 plums.
#### 6
The answer is: 6
Below is a math problem. Provide a detailed, step-by-step solution.

### Problem:
If Tanya bought 6 pears, 4 Granny Smith apples, 2 pineapples, and a small basket of plums, all placed in a single paper bag, but lost half of the fruit while walking home, leaving only 9 pieces in the bag, how many plums did she originally purchase?

### Answer:
