The common ratio between terms is 3, so the sequence has general 
-th term
for 
. The term exceeds 7000 when
which means the first time 
exceeds 7000 occurs when 
. Indeed,
while the previous term would have been
40000=5000e^30r
40000/5000=e^30r
R=(log(40000/5000)/log(e))/30)*100
R=6.93%
12 to 16 because all ratios are equivalent
The store clerk gave the customer:
Gas. . . . . . . . . 17.01
$5 ticket . . . . . . 5
$3 ticket . . . . . . 3
2 x $1 ticket . . . 2
Total. . . . . . . $27.01
The customer gave the store clerk:
$5 ticket . . . 5
$2 ticket . . . 2
cash. . . . . 100
Total. . . . $107
The store clerk owes the customer ($107 - $27.01) = $ 79.99 .
