Question

Need help solving these problems.

I know it is A = P(e)^rt

I did that with the problems and keep getting the wrong answers.

Answer 1

Remember, the 12% is per year

Answer 2

yeah so the ^(.12)(20) right?

Answer 3

well, \(e\) is for continuous, so this case don' t use \(e\) :)

Answer 4

A=P(1+r)^t

Answer 5

so the last problem I tried would be 2000/1.2^20?

Answer 6

Well, it's compounded monthly, so the formula would be \(A=$2000(1+\frac{12\%}{12})^t\), where \(t\) is the number of months

Answer 7

And he's not asking you for the interest, so don't subtract \($2000\) :)

Answer 8

OK, let me do part b for you, and see if you can do the rest by yourself :)

Answer 9

Principal after 6 months
\(=$2000(1+\frac{12\%}{12})^6\)
\(\approx$2123.04\) (correct to the nearest cent)

Answer 10

why over 12? becuase that how many years in a month? and what if the time was years instead of months for the exponent?

Answer 11

or just convert the months to years right?

Answer 12

Then you'll have to multiply the number of years by \(12\) :)

Answer 13

no years to months

Answer 14

years to months*

Answer 15

lol

Answer 16

ok and the 12% was over 12 becuase 12 is number of years in months right

Answer 17

Because the 12% is per year and its compounded monthly :)

Answer 18

Are you all right? :)

Answer 19

lol yea trying to workem out

Answer 20

what've u got?

Answer 21

2000*0.04^240 for last one

Answer 22

for last one just trying to do the power

Answer 23

it's not 0.04, it's still \((1+\frac{12\%}{12})\) which is \(1.01\)

Answer 24

yea, idk why or how i got mine but redid it an got that. just trying to do that to the power of 240

Answer 25

use google search as a calculator

Answer 26

or Wolfram|Alpha

Answer 27

i get $21875.10 for last one

Answer 28

21785.11*

Answer 29

what if the world problem says year compounded semiannually

Answer 30

sorry was browsing

Answer 31

then the formula would be \($2000(1+\frac{12\%}2)^t\), where \(t\) is the number of half-year

Answer 32

so 3 years would be 1.5

Answer 33

6

Answer 34

oh thought you ment by half years like litterlaly half

Answer 35

yep :)

Answer 36

General formula: \(A=P\times(1+\frac{r}{y})^{yt}\), where \(r\) is the interest per annum, \(y\) is the number of times compounded in a year, \(t\) is the number of years.

(Don't google this as the symbols are created by me)

Answer 37

Ah I got those 6, but trying the foumals with these one I get it wrong the first one I did

1600( 1 + 4.25/2 )^6

Answer 38

sorry for late reply

Answer 39

it's \(r\%\) that is \(4\frac14\%\)

Answer 40

and read the question carefully, the second question is asking the reverse

Answer 41

4 1/4 is 4.25 right?

Answer 42

yep :)

Answer 43

So my calculation above was right?