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Sophie had 8200$ on her bankaccount.

After some time she had recived 164$ in interest rates. The rate was on 2,5%.

How many days did it take to get 164$?

 

Is this right?

 

8200*0,025 = 205

 

205/365 = 0,5616

 

164/0,5616 = 292 days

 

or is there any eaiser way to do it?

 Feb 1, 2016

Best Answer 

 #4
avatar+129850 
+5

8200 + 164 = 8364

 

So.....assuming the interest rate is the annual rate, we have :

 

8364  = 8200(1 + .025)^t       divide both sides by 8200

 

8364/8200 = (1.025)^t      take the log of both sides

 

log [8364/8200]  = log(1.025)^t      and we can write

 

log [ 8364/8200] = t* log(1.025)      divide both sides by log (1.025)

 

log[8364/8200] / log(1.025)  = t  = .8   of one year ≈   .8 x 365  ≈ 292 days

 

 

 

cool cool cool

 Feb 1, 2016
 #1
avatar+10 
0

2.5% = 2.5/100 = 5/200 = 1/40

 

8200*(1/40) = 8200/40 = 205

 

Less then one day?

 

 

 

You don't give enough information.

 Feb 1, 2016
 #2
avatar
+5

8,200 X [.025*d / 365] =164.00, solve for d.

 

Solve for d: 0.561644 d = 164. Divide both sides of 0.561644 d = 164. by 0.561644: (0.561644 d)/0.561644 = 164./0.561644 0.561644/0.561644 = 1: d = 164./0.561644 164./0.561644 = 292.: Answer: | | d = 292.

 Feb 1, 2016
 #3
avatar+18 
+10

Original post was posted non-logged-in so here we go with some more details:

 

Sophie had 8200$ on her bankaccount.

After some time she had recived 164$ in interest rates. The rate was on 2,5%.

How many days did it take to get 164$?

 

8200$*0,025 = 205$

(0,025 because of 2,5% interest rate = 0,025, and 205$ = Interest rates over a year)

 

205$/365 = 0,5616$          

(365 because of 365 days a year)

 

164$/0,5616$ = 292 days 

(164$ because of interest rates in $ and 0,5616$ because of the reciving per day)

 Feb 1, 2016
edited by yombo  Feb 1, 2016
edited by yombo  Feb 1, 2016
edited by yombo  Feb 1, 2016
 #4
avatar+129850 
+5
Best Answer

8200 + 164 = 8364

 

So.....assuming the interest rate is the annual rate, we have :

 

8364  = 8200(1 + .025)^t       divide both sides by 8200

 

8364/8200 = (1.025)^t      take the log of both sides

 

log [8364/8200]  = log(1.025)^t      and we can write

 

log [ 8364/8200] = t* log(1.025)      divide both sides by log (1.025)

 

log[8364/8200] / log(1.025)  = t  = .8   of one year ≈   .8 x 365  ≈ 292 days

 

 

 

cool cool cool

CPhill Feb 1, 2016

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