1. The problem asks: How long in years will ₱12,000 earn ₱3,600 at 10% simple interest? 2. The formula for simple interest is: $$I = P \times r \times t$$ where $I$ is the interest earned, $P$ is the principal, $r$ is the annual interest rate (in decimal), and $t$ is the time in years. 3. We know: - $I = 3600$ - $P = 12000$ - $r = 10\% = 0.10$ We need to find $t$. 4. Rearranging the formula to solve for $t$: $$t = \frac{I}{P \times r}$$ 5. Substitute the known values: $$t = \frac{3600}{12000 \times 0.10}$$ 6. Calculate the denominator: $$12000 \times 0.10 = 1200$$ 7. So: $$t = \frac{3600}{1200}$$ 8. Simplify the fraction: $$t = \cancel{\frac{3600}{1200}} = 3$$ 9. Therefore, the time is 3 years. **Final answer:** $3$ years.