Question

The 30th term of the AP 10, 7, 4, .... is
(a) −87
(b) 87
(c) 77
(d) −77

Answer 1

Correct option is D. $-77$

Given AP is $10,7,\mathrm{4..}$

Here, $a=10,d=7-10=-3$ and $n=30$

$\therefore a_{30}=10+(30-1)(-3)$

$=10-\left(29\right)\left(3\right)$

$=-77$