又一難數= =..

啦啦啦

if the interest rate is 5% p.a. on simple interest , how long does it take for the amount to

be equal to twice the principal ?

嘩,,可能我唔係好明條問題,,
時間 --冇
本金 -- 冇
amount -- 冇
利潤都唔知 -- 冇
點計= =....

[ 本帖最後由 啦啦啦 於 3/10/2007 06:53 PM 編輯 ]

STEVE

原帖由 啦啦啦 於 3/10/2007 06:49 PM 發表

                               
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if the interest rate is 5% p.a. on simple interest , how ling does it take fir the amount to

be equal to twice the principal ..

嘩,,可能我唔係好明條問題,,
時間 --冇
本金 -- 冇
amount -- 冇
...

interest = P*t*5%

amount = P(1+t*5%) = 2P
t*5% = 1
t = 20 years

[ 本帖最後由 STEVE 於 19/10/2007 07:32 PM 編輯 ]