Question

Find the 6th term from end of the AP.
$17,14,11,.......,-40$

• A. $25$
• B. $-25$
• C. $-28$
• D. $28$

Answer 1

The correct option is B $-25$

First, we will find the number of terms in the sequence.

$t_n=a+(n-1)d⟹-40=17+(n-1)(-3)⟹-40=-3n+20orn=20$.

So, there are a total of 20 terms in the sequence.

The 6th term from the last is same as the 15th term from the first.

Hence, $t_{15}=17+(15-1)(-3)⟹t_{15}=17-14(-3)⟹t_{15}=-25.$.