Answer:
The geometric series is:
2+14+98+686
Explanation:
The geometric series is a series in which each term of the series is a constant multiple of the preceding term of the series.
a)
6+13+20+27
This is not a geometric series but is a arithmetic series.
Since, each term is increased from the preceding term by 7.
Since, 6+7=13
13+7=20
20+7=27
b)
7+21+35+45
This is not a geometric series.
Since 7×3=21
But 21×3=63
But the next term that is given is: 28 and not 63
c)
14+21+28+35
This is a arithmetic sequence.
Since
14+7=21
21+7=28
and 28+7=35
d)
2+14+98+686
This is a geometric sequence.
Since,. we get a common ratio i.e. a term which when multiplied to each term of sequence gives the next term of the series.
i.e. 2×7=14
14×7=98
98×7=686