Question

In an AP given that the first term is a=54 the common difference d=-3 the nth term is an=0 find n and the sum of the first n terms

Answer 1

Answer:

n=19 Sn=513

Step-by-step explanation:

an=a+(n-1)d

0 =54+(n-1)(-3)

0 =54-3n+3

3n=57

n=19

Sn=n/2(a+l)

=19/2(54+0)=27×19=513