Sequence(ii)

c)
The number of visitors to Hong Kong in 2002 is
13000000 * (1 + 5%)^2 = 14332500.
The total number of years to count = 2047 - 2002 + 1 = 46. We set up a geometric sequence with 14332500 as the first term, 1 + 5% = 1.05 as the common ratio, then the answer can be obtained by summing up to the 46th term, i.e.,
sum = 14332500 * (1.05^46 - 1) / (1.05 - 1) = 2417680108

di) Between 2002 and 2047, the first leap year is 2004 and last leap year is 2044.
The number of leap years = (2044 - 2004) / 4 + 1 = 11

ii)
The number of visitors to Hong Kong in 2004 is
13000000 * (1 + 5%)^4 = 15801581.25
We set up a geometric sequence with 15801581.25 as the first term, 1.05^4 as the common ratio, then the answer can be obtained by summing up to the 11th term, i.e.
sum = 15801581.25 * ((1.05^4)^11 - 1) / (1.05^4 - 1) = 554113508 (nearest integer)