How many minutes passed from 2: 15 to 2: 30 and how many minutes passed from 6: 05 to 6: 25 ?

From 2:15 to 2:30, 15 minutes has passed and from 6:05 to 6:25 20 minutes has passed

Sales acting like this would produce a geometric sequence with a common ratio of 90/100 or 0.9 because each term would be 0.9 time the previous term.

The sum of a geometric sequence is:

s(n)=a(1-r^n)/(1-r), a=initial term, r=common ratio, n=term number, in this case:

s(n)=495000(1-0.9^n)/(1-0.9)

s(n)=495000(1-0.9^n)/(0.1)

s(n)=4950000(1-0.9^n) so

s(6)=4950000(1-0.9^6)

s(6)=$2630632.95