What's this man's total income for working 29 days?

Question

Suppose you go to a company that pays 0.02 for the first day, 0.04 for the second day, 0.08 for the third day and so on. If the daily wage keeps doubling, what will your total income be for working 29 days ?

Total Income = ?

Answer 1

it's a geometric series

a1 = 2 cents

r = common ratio = 2

sn = a1(r^n-1)/(r-1)

s29 = 2(2^28 -1)(2-1)

= 2(2^28 -1) cents

= .02(2^28-1) dollars