1. The variable y varies directly with s and inversely with t. Find the percentage change in y if s increases by 14% and t increases by 20%.
Ans: decreases by5%.
2. A sum of $10000 is deposited at a rate of 4% per annum, compounded half-yearly. Find the amount of money that will have accumulated by the end of the third year.
Ans; 11262
Anyone who knows how to do these, please do it immediately with all workings shown. Extra marks will be rewarded for good workings!! =]
Please show all workings!
Maths唔識抵死題=]
2010-12-24 3:15 am
回答 (2)
2010-12-24 3:31 am
✔ 最佳答案
1. y=ks/t, k is a constantk(1+14)s/(1+20)t = 0.95ks/t = 0.95 y
so it decreased
(y - 0.95y)/y*100% = 5%
2. amount = 10000(1+ 4%/2)^6 = 11261.6 ~= 11262
2010-12-26 17:08:55 補充：
formula for calculating compound interest:
A = D(1+ r*y)^d
A = amount
D = deposit
r = rate per annum
y = how it compounds (yearly, monthly, etc)
d = duration
2010-12-26 10:47 pm
What is the formula for calculating compound interest???
收錄日期: 2021-04-23 20:43:14
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20101223000051KK01071