JEE Main 2026 Mathematics question
The first term of an A.P. of 30 non-negative terms is . If the sum of this A.P. is the cube of its last term, then its common difference is:
Answer: (A)
Solution
With d = 5/87, the last term l = 10/3 + 29(5/87) = 5, and the sum = 15(10/3 + 5) = 125 = 5³ = l³, confirming the value.