Find the 12th term from the end of the AP – 2, - 4, - 6, …, - 100.
Given AP, – 2, - 4, - 6, …, - 100.
Here,
first term, a = - 2
common difference, d = - 4 – (2) = - 2
last term, l = - 100.
We know that, the nth term 'an' of an AP from the end is
an = l - (n - 1)d
where l is the last term and d is the common difference.
12th term from the end,
a12 = - 100 - (12 - 1) - 2
= - 100 + 22
= - 78
Hence, the 12th term from the end is - 78