有條數想大家教我計

First month : 10,000
Second month : 10,000(1 + 5%) + 10,000 = 10,000(1.05) + 10,000
Third month : [10,000(1.05) + 10,000]( 1 + 5%) + 10,000
= 10,000(1.05)^2 + 10,000(1.05) + 10,000.
After 30 years ( 360 months) = 10,000(1.05)^359 + 10,000(1.05)^358 +.............. + 10,000(1.05)^2 + 10,000(1.05) + 10,000.
= 10,000[1.05^359 + 1.05^358 + 1.05^357 + ....... + 1.05^ 2 + 1.05 + 1]
=10,000[ 1.05^360 - 1]/0.05 = 10,000 x 849527928.1
= 8495279 million.

不知道你想問什麼.
你是每月增加一萬, 還是每月只增加 5%?
為什麼是"約每月 5%"? 這樣沒有人可以告訴你確實答案.