Question

how many terms of ap 27 24 21 should be taken so that their sum is 0

Answer 1

Answer:

S=n/2(2a+(n-1)d)

=>0=n/2(2×27+(n-1)(-3))

=>0=54-3n+3

=>3n=57

=>n=57/3=19

therefore 19 terns of the given AP must be added to give the sum 0

Answer 2

a=27
d=-3
n=?
Sn=0
Sn=n/2(2a+(n-1)d)
0=n/2(54+(n-1)*-3)
0=n(54-3n+3)
57-3n=0
3n=57
n=57/3
n=19