Question

megan hughes deposits 2100 in an account that pays simple interest. when she withdraws her money 11 months later, she receives $2138.50. what rate of interest did the account pay for?

Answer 1

The rate at which the account pay the deposit is 2 %

Explanation:

Given as :

The principal amount deposited in account = $2100

The rate of interest = r % simple interest annually

The time period = 11 months =
`(11)/(12)` year

The amount received = $2138.50

Now, From Simple Interest method

Simple Interest =
`(\textrm Principal* \textrm rate* \textrm time)/(100)`

Or, Interest =
`(2100* r* (11)/(12))/(100)`

Or, Interest =
`(21* r* 11)/(12)`

Or, Interest = 19.25 r

Now, Interest = Amount - Principal

So, 19.25 r = $2138.50 - $2100

Or, 19.25 r = $38.5

∴ r =
`(38.5)/(19.25)`

I.e r = 2

So, rate of interest = r = 2 %

Hence The rate at which the account pay the deposit is 2 % Answer