Each blouse requires 20 black dots and each dot requires 10 ml of black dye, so each blouse requires 20 * 10 = 200 ml of black dye.
If Jenna needs to dye 100 blouses, she will need a total of 100 * 200 = 20,000 ml of black dye.
Since each bottle of dye contains 400 ml, Jenna will need to purchase 20,000 / 400 = 50 bottles of dye.
#### 50
The answer is: 50
Below is a math problem. Provide a detailed, step-by-step solution.

### Problem:
If each blouse requires 20 black dots and each dot requires 10 ml of black dye, how many 400-ml bottles of dye does Jenna need to purchase in order to dye 100 blouses?

### Answer:
