Give the step-by-step reasoning process and then the final answer. The epic poem currently contains 24 lines. If a person adds 3 lines to the poem every month, in how many months will the poem contain 90 lines?
If the epic poem currently contains 24 lines, the total number of lines added for it to reach 90 is 90 - 24 = 66 lines. If a person adds 3 lines to the poem every month, it will take 66 / 3 = 22 months for the poem to contain 90 lines.
The final answer: 22.