The 20th term from the end of the A.P. 3, 8, 13, ..., 253 is:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 158
Read from the end, the A.P. starts at its last term 253 and goes down by the common difference 5 at every step, so the 20th term from the end is 19 steps below 253.
Common difference \(d=8-3=5\)
20th term from the end \(=l-(20-1)d=253-19\times5\)
\(=253-95=158\)