Question

which term of AP 100,90,80....is 0

Answer 1

a1=100

d=a2-a1

d=90-100=-10

an=0

0=a+(n-1)d

0=100+(n-1)-10

-100=-10n+10

-10n=-110

n=11..

Answer 2

a1= 100
d= a2 - a1
90-100
-10=d
a+3d= 100+3(-10)
= 100-30
=70
a+10d = 100+ 10(-10)
=100-100
=0 ..
so therefore .. 11th term is 0