Explanation:

- Let's assume the total number of workers in the company is \( x \).

- 75% of the workers are skilled, so the number of skilled workers is \( 0.75x \).

- The remaining 25% are unskilled, so the number of unskilled workers is \( 0.25x \).

- 84% of skilled workers are permanent, making the number of permanent skilled workers \( 0.84 \times 0.75x \).

- 28% of unskilled workers are permanent, making the number of permanent unskilled workers \( 0.28 \times 0.25x \).

- The total number of temporary workers is 180, so:

$$

(0.75x - 0.84 \times 0.75x) + (0.25x - 0.28 \times 0.25x) = 180

$$

- Simplifying, you get:

$$

0.75x(1 - 0.84) + 0.25x(1 - 0.28) = 180

$$

$$

0.75x(0.16) + 0.25x(0.72) =180

$$

$$

0.12x + 0.18x = 180

$$

$$

0.30x = 180

$$

$$

x = 600

$$

Correct Answer: Option 4: 600

.