how many terms of an ap 65,60 ,55 ... be taken so that their sum =0
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Answer:
27
Step-by-step explanation:
A P is 65,60,55,....
a=65
d=-5
Sn= 0
Sn=n/2[2a+(n-1) d]
0=n/2[2*65+(n-1)-5]
0=n/2[130-5n+5]
0=n/2(135-5n)
0=n/2 * 5(27-n)
0=5n/2 (27-n)
0=5n(27-n)
0=27-n or 0=5n
n=27 or n=0
but n=0 is not possible
so n=27
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