Question

Samantha has $1,290 in a savings account that pays 4% simple interest. How much interest will she earn in 9 months? How much will she have in the account altogether?

Answer 1

Given:

Principal = $1290

Rate of simple interest = 4%

Time = 9 months

To find:

The interest and total saving in the account altogether.

Solution:

The formula for simple interest is

$I=\dfrac{P\times r\times t}{100}$      ...(i)

where, P is principal, r is rate of interest and t is time in years.

We know that,

$12\ months=1\ year$

$1\ month=\dfrac{1}{12}\ year$

$9\ months=\dfrac{9}{12}\ year$

$9\ months=0.75\ year$

Putting P=1290, r=4 and t=0.75 in (i), we get

$I=\dfrac{1290\times 4\times 0.75}{100}$

$I=\dfrac{3870}{100}$

$I=38.70$

So, the simple interest is $38.70.

Total savings is

$1290+38.70=1328.70$

Therefore, the total amount in the account altogether is $1328.70.