1. The problem involves a sequence of monthly deposits starting at 500000 and increasing by 100000 each month. 2. We identify the sequence as an arithmetic sequence with first term $a_1=500000$ and common difference $d=100000$. 3. The amounts for the first three months are given as 500000, 600000, and 700000 respectively, confirming the arithmetic pattern. 4. To find the total amount deposited over $n$ months, we use the formula for the sum of an arithmetic series: $$ S_n = \frac{n}{2} (2a_1 + (n-1)d) $$ 5. For example, if we want to find the total after 12 months: $$ S_{12} = \frac{12}{2} (2 \times 500000 + (12-1) \times 100000) = 6 (1000000 + 1100000) = 6 \times 2100000 = 12600000 $$ 6. This matches the value Rp12.600.000,00 mentioned, confirming the calculation. 7. Similarly, the total after 16 months would be: $$ S_{16} = \frac{16}{2} (2 \times 500000 + (16-1) \times 100000) = 8 (1000000 + 1500000) = 8 \times 2500000 = 20000000 $$ 8. The value Rp19.920.000,00 is close to this, possibly due to rounding or a slightly different number of months. Final answer: The total amount deposited after $n$ months is given by $$ S_n = \frac{n}{2} (2 \times 500000 + (n-1) \times 100000) $$ This formula can be used to calculate the total deposits for any number of months in this sequence.