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Mathematics
Mathematics
Problem
The usual formula for the sum of the first
n
n
n
terms of a geometric progression is not valid for which value of the common ratio
r
r
r
? a)
r
=
0
r=0
r
=
0
b)
r
=
2
r=2
r
=
2
c)
r
=
1
r=1
r
=
1
d)
r
=
−
1
r=-1
r
=
−
1
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