we know that
Erica
The sequence in minute is
15,30,60,120,240,480,960
This is a geometric sequence
where
r=30/15=2 ----> common ratio
the recursive formula For n>1 is equal to

Find out the explicit formula

where
a1=15
r=2

Naomi
we have the sequence in hours
3 3.5 4 4.5 5 5.5 6
This is an arithmetic sequence
where
d=3.5-3=0.5 ----> the common difference
the recursive formula For n> 1 is equal to

Find out the explicit formula

where
a1=3
d=0.5
substitute
