In an A.P., the sum of first four terms is 20 and the sum of first three terms is 12. Find the fourth term.
Answer: B
The fourth term \(a_4\) is the difference between the sum of the first four terms (\(S_4\)) and the sum of the first three terms (\(S_3\)). \(a_4 = S_4 - S_3 = 20 - 12 = 8\).