Answer:
The rate at which the account pay the deposit is 2 %
Step-by-step explanation:
Given as :
The principal amount deposited in account = $2100
The rate of interest = r % simple interest annually
The time period = 11 months = [tex]\frac{11}{12}[/tex] year
The amount received = $2138.50
Now, From Simple Interest method
Simple Interest = [tex]\dfrac{\textrm Principal\times \textrm rate\times \textrm time}{100}[/tex]
Or, Interest = [tex]\dfrac{2100\times r\times \frac{11}{12}}{100}[/tex]
Or, Interest = [tex]\frac{21\times r\times 11}{12}[/tex]
Or, Interest = 19.25 r
Now, Interest = Amount - Principal
So, 19.25 r = $2138.50 - $2100
Or, 19.25 r = $38.5
∴ r = [tex]\frac{38.5}{19.25}[/tex]
I.e r = 2
So, rate of interest = r = 2 %
Hence The rate at which the account pay the deposit is 2 % Answer
