Some mathematics question of percentage...
Question 1: stephanie deposited $15000 at the beginning of every year. The interest was calculated at 7% p.a. compounded yearly. find, at the end of 5 years, the amount he received and the total interest he got.
(correct the answers to the nearest dollar.)
Question 2:A man borrows $20000 from a bank at 10%p.a. and repays $5000 at the end of each year. Find the amount he still owes after the fourth payment.
Thank you very much!
About percentage......
2011-02-13 6:00 am
回答 (4)
2011-02-13 11:30 am
✔ 最佳答案
Question 1:The amount he received
= $15000 x (1 + 7%) + $15000 x (1 + 7%)^2 + $15000 x (1 + 7%)^3 + $15000 x (1 + 7%)^4 + $15000 x (1 + 7%)^5
= $15000 x (1.07 + 1.07^2 + 1.07^3 + 1.07^4 + 1.07^5)
= $15000 x (1.07 + 1.07x1.07 + 1.07x1.07^2 + 1.07x1.07^3 + 1.07x1.07^4)
= $15000 x 1.07 x (1.07^5 - 1) / (1.07 - 1)
= $92299 (to the nearest dollars)
Total interest he got
= $92299 - ($15000 x 5)
= $17299
Question 2:
Amount he still owes after the first payment
= $20000 x (1 + 10%) - 5000
= $17000
Amount he still owes after the second payment
= $17000 x (1 + 10%) - 5000
= $13700
Amount he still owes after the third payment
= $13700 x (1 + 10%) - 5000
= $10070
Amount he still owes after the third payment
= $10070 x (1 + 10%) - 5000
= $6077
參考: micatkie
2011-02-17 2:30 am
2011-02-13 9:21 pm
micatkie (:
You are correct!
You are correct!
2011-02-13 6:29 am
Question 1
Total received = $15000 x (1+7%)^5
=21038.28
=21038 (nearest dollar)
total interest = total received - $15000
=21038-15000
=6038
Question 2
Principal x (1+interest rate)^no. of years -
[(1+interest rate)^no. of years - 1]/interest rate x monthly repayment
if interest is paid monthly, the interest rate should be divided by 12
and years should be replaced by no. of months
$20000 x (1+10%)^5 - [(1+10%)^5-1]/10% x 5000
=32210.2-30525.5
=1684.7
Total received = $15000 x (1+7%)^5
=21038.28
=21038 (nearest dollar)
total interest = total received - $15000
=21038-15000
=6038
Question 2
Principal x (1+interest rate)^no. of years -
[(1+interest rate)^no. of years - 1]/interest rate x monthly repayment
if interest is paid monthly, the interest rate should be divided by 12
and years should be replaced by no. of months
$20000 x (1+10%)^5 - [(1+10%)^5-1]/10% x 5000
=32210.2-30525.5
=1684.7
收錄日期: 2021-04-13 17:50:25
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