中五數學-百分率問題

a) 每月薪金 = $9375/75% = $12500
每月儲蓄金額 = 薪金*(1-75%) = $12500*25% = $3125
b) 十年後第一部份(40%):
$3125*60%*(1+2%)*10 = $19125
十年後的總儲蓄 = $19125/40% = $47812.5
十年後第二部份(60%):
$3125*(1-60%)*(1+r/4)^40 = $47812*60%
$1250*(1+r/4)^40 = $28687.5
(1+r/4)^40 = 22.95
1+r/4 = 1.081483
r/4 = 0.081483
r = 0.32593
所以複利息計算的年利率 = 32.59%

a) 薪金: $9375除75%=$12,500
儲蓄: $12,500-$9375=$3125

b) 我冇時間打啊! = 32.59啊^^

A.

邱先生每月薪金: $9,375 / 75% = $12,500

邱先生每月儲蓄金額: $12,500 - $9370 = $3,125