Question

Find the $20th$ term from the last term of the $AP:3,8,13,.....,253$

• A. 158
• B. 155
• C. 143
• D. 147

Answer 1

The correct option is A 158

$a=3,d=5$
$253=3+5(n-1)$
Or, $5(n-1)=250$
Or, $n-1=50$
Or, $n=51$
So, the $20th$ term from the last term $=51-19=32nd$ term
Now, $n_{32}=3+5\times 31=158$