Question

The second term of an A.P. is 13 and its fifth term is 25. The common difference of the A.P. is:

• A. \( 5 \)
• B. \( 4 \)
• C. \( 3 \)
• D. \( 6 \)

Hint:

For finding the common difference \( d \), use: \[ d = \frac{a_m - a_n}{m - n}. \]

Answer 1

The Correct Option is B

Using the formula:
\[ a_n = a + (n-1)d. \] For the second term:
\[ a + d = 13 \quad \cdots (1). \] For the fifth term:
\[ a + 4d = 25 \quad \cdots (2). \] Subtracting equation (1) from equation (2):
\[ (a + 4d) - (a + d) = 25 - 13. \] \[ 3d = 12. \] \[ d = 4. \]