Question

which term of an a.p24,21,18...is the first negative term​

Answer 1

24,21,18,........

a=24, d = 21-24 = -3

let us consider that nth term be first -ve term

so, an<0

this means that

a+(n-1)d.<0

24+(n-1)(-3)<0

24-3n+3<0

27-3n<0

-3n<-27

3n>27

n>9

Hence , 10 th term is first -ve term