Question

how many terms of the AP 27 24 21 and so on should be taken so that their sum is zero ​

Answer 1

Answer:

Step-by-step explanation: a=27

D=24-27=-3

S=0

Sn=n/2(2×27+(n-1))-3

0=n(54-3n+3)

0=n(57-3n)

0=57-3n

3n=57

n=19

Answer 2

Answer:

n=17

Step-by-step explanation:

Sn=0,a=27,d=24-27=-3,n=?

Sn=n/2{2a+(n-1) d}

0 =n/2(54-3n-3)

0 =n×(51-3n)

0 =51n-3n^2

n^2/n=51/3

n= 21