Question

Which term of the A.P $101,97,......$ is its first negative term?

• A. $26$
• B. $25$
• C. $28$
• D. $27$

Answer 1

The correct option is D $27$

Given, $a=101,d=97-101=-4$
$n^{th}$ term $t_n=a+(n-1)d<0$ ( negative number is lesser than zero)
$101+(n-1)(-4)<0$
$101-4n+4<0$
$105-4n<0$
$105<4n$
$26<n$
So $t_n=27$