Question: User: 36-40. At what rate of simple interest will ₱7500 earns ₱2050 in 3 years and 4 months?
1. **State the problem:** We need to find the rate of simple interest $r$ that will make ₱7500 earn ₱2050 in 3 years and 4 months.
2. **Formula for simple interest:**
$$I = P \times r \times t$$
where $I$ is the interest earned, $P$ is the principal, $r$ is the rate per year (in decimal), and $t$ is the time in years.
3. **Convert time to years:**
3 years and 4 months = $3 + \frac{4}{12} = 3 + \frac{1}{3} = \frac{10}{3}$ years.
4. **Plug in known values:**
$$2050 = 7500 \times r \times \frac{10}{3}$$
5. **Solve for $r$:**
$$r = \frac{2050}{7500 \times \frac{10}{3}} = \frac{2050}{7500 \times \frac{10}{3}}$$
6. **Simplify denominator:**
$$7500 \times \frac{10}{3} = 7500 \times \frac{10}{3} = \frac{7500 \times 10}{3} = \frac{75000}{3}$$
7. **Calculate $r$:**
$$r = \frac{2050}{\frac{75000}{3}} = 2050 \times \frac{3}{75000} = \frac{6150}{75000}$$
8. **Simplify fraction:**
$$r = \frac{6150}{75000} = \frac{\cancel{6150}}{\cancel{75000}} = \frac{41}{500} = 0.082$$
9. **Convert to percentage:**
$$r = 0.082 \times 100 = 8.2\%$$
**Final answer:** The rate of simple interest is $8.2\%$ per year.