Question

Macy currently has a balance of $3,418.82 in an account earning simple interest. Eighteen years ago she opened the account with an initial deposit of $2,481. What is the interest rate on the account?

Answer 1

is anyone there any members can help me please

Answer 2

do you happen to have the Interest Rate Formula?

Answer 3

no :(

Answer 4

or, I should say, if you stick "X" amount in the bank today, and they say they'll give you 5percent interest, how much would you expect in 1year?

Answer 5

would you expect X+[5percent of X]? after 1 year?

Answer 6

ok, what's 10% of 100? :)

Answer 7

10

Answer 8

ok, so if you put $100 in the bank, and they they'd give you 10 yearly interest, after 1 year, you'd expect $100+[10% of $100 = $10], thus $110 :)

Answer 9

Macy originally put $2481, after 18 years, with yearly interest, it became $3,418.82
so
$3,418.82 = $2481 + [$2481 * RATE] *18years

Answer 10

it ask for the interest rate

Answer 11

7.7%

1.5%

5.6%

2.1%

Answer 12

Even if it's earning simple interest, the interest will compound annually.

Answer 13

$$
A= 3,418.82\\
P= 2,481\\
r = ?
-------------\\
A=P+ Prt \implies P(1+rt)\\
A-P=Prt\implies \color{blue}{\cfrac{A-P}{Pt}=r}
$$

Answer 14

woops, ahemm

Answer 15

7.7%

1.5%

5.6%

2.1%

these are the answrs

Answer 16

$$
A= 3,418.82\\
P= 2,481\\
\color{blue}{r = ?}\\
-------------\\
A=P+ Prt \implies P(1+rt)\\
A-P=Prt\implies \color{blue}{\cfrac{A-P}{Pt}=r}
$$

Answer 17

@jcdavi34 what does that give you?

Answer 18

ohh,and T=18, 18years :/

Answer 19

i got 2.1%

Answer 20

$$
A= 3,418.82\\
P= 2,481\\
t=18\\
\color{blue}{r = ?}\\
-------------\\
A=P+ Prt \implies P(1+rt)\\
A-P=Prt\implies \color{blue}{\cfrac{A-P}{Pt}=r}
$$
what do you get?

Answer 21

2.1% that is :)

Answer 22

thanks!