The 5th term of an arithmetic sequence is 25, and the 12th term is 60. What is the first term of the sequence?

✓ Correct Answer: Option A

Let 'a' be the first term and 'd' be the common difference. a + 4d = 25 and a + 11d = 60. Subtracting the first from the second gives 7d = 35, so d = 5. Substitute d=5 into a + 4d = 25 to get a + 4(5) = 25, which means a + 20 = 25, so a = 5.