Question

Which term of the A.P. :$171,167,163,......$ is its first negative term ?

Answer 1

$171,167,163$

$a+(n-1)d<0\Rightarrow 171+(n-1)(-4)<0$

$171-4n+4<0$

$-4n+175<0$

$4n-175>0$

$n>\frac{175}{4}>43$

${43}^{th}$ term would be negative