1. Stating the problem: Simplify the expression $$\frac{28}{70} \cdot \frac{30}{12}$$. 2. Use the rule for multiplying fractions: multiply the numerators together and the denominators together. 3. Multiply numerators: $$28 \times 30 = 840$$. 4. Multiply denominators: $$70 \times 12 = 840$$. 5. The expression becomes $$\frac{840}{840}$$. 6. Simplify the fraction by canceling common factors: $$\frac{\cancel{840}}{\cancel{840}} = 1$$. 7. Final answer: $$1$$.