Math
posted by Amy .
invested 2000
gains 0.2 every odd numbered month
final value after first month?
i've tried solving this with a formula, but every formula i come up with is wrong.
Could someone tell me how to solve this and plug in the right numbers into a formula?

Are we to assume that there is a 20% gain for every oddnumbered month and for the evennumbered months the investment stays constant?
Since the "first" month would be oddnumbered, the amount after the first month would simply be
2000(1.2) = 2400
the "formula" would simply be
amount = 2000(1 + .2)^1 
for every evennumbered number month there is a 15% gain.