The sequence is geometric with first term
a
1
=
100
and common ratio
r
=
0.5
Explanation:
a
1
=
100
,
a
2
=
50
,
a
3
=
25
,
a
4
=
25
2
,
a
5
=
25
4
...
50
100
=
0.5
,
25
50
=
0.5
,
25
2
25
=
0.5
,
25
4
25
2
=
0.5
∴
a
2
a
1
=
a
3
a
2
=
a
4
a
3
=
a
5
a
4
=
0.5
The ratio of successive term and preceeding term is constant
(
r
=
0.5
)
. Therefore the sequence is geometric whose first
term is
a
1
=
100
and common ratio is
r
=
0.5
[Ans]