Use the simple interest formula to find the unknown quantity
I = $13.98
P=
r = 3.6%
t = 4 months
Using the simple interest formula, the unknown quantity "P" principal = $ 1165
Given that,
I = $ 13.98 which means simple interest = $ 13.98
r = 3.6 %
t = 4 months = [tex]\frac{4}{12}[/tex] years
P = ?
Here we have to find the value of "P" principal sum
The formula for simple interest is given as:
[tex]\text {simple interest }=\frac{P \times n \times r}{100}[/tex]
Where "P" is the principal
"n" is the number of years
"r" is the rate of interest
Substituting the values in formula,
[tex]\begin{array}{l}{13.98=\frac{P \times 3.6 \times 4}{100 \times 12}} \\\\ {P=\frac{13.98 \times 12 \times 100}{3.6 \times 4}} \\\\ {P=\frac{13.98 \times 1200}{14.4}=1165}\end{array}[/tex]
Thus the unknown quantity "P" principal = $ 1165
