1. **State the problem:** Leona answered all 40 questions on a test and got 90% of them correct. We need to find how many questions she answered correctly. 2. **Formula used:** To find the number of correct answers, use the formula: $$\text{Number correct} = \text{Total questions} \times \frac{\text{Percentage correct}}{100}$$ 3. **Apply the values:** $$\text{Number correct} = 40 \times \frac{90}{100}$$ 4. **Simplify the fraction:** $$40 \times \frac{\cancel{90}}{\cancel{100}} = 40 \times 0.9$$ 5. **Calculate the product:** $$40 \times 0.9 = 36$$ 6. **Answer:** Leona answered **36** questions correctly.