The correct option is B l−(n−1)d
Given, first term = a , common difference = d and last term = l.
Corresponding AP=a,a+d,...,l
Now, reverse the AP, we again get an AP.
Reverse AP=l,l−d,...,a
Last term =a , first term =l and common difference = 2nd term - 1st term =l−d−l=−d
Therefore, nth term
= first term + (n-1)(common difference)
=l+(n−1)(−d)=l−(n−1)d