Answer:
N = 0.0225P
Step-by-step explanation:
[tex]\boxed{\begin{minipage}{7 cm}\underline{Simple Interest Formula}\\\\$ I = Prt$\\\\where:\\\\ \phantom{ww}$\bullet$ $I =$ interest accrued \\ \phantom{ww}$\bullet$ $P =$ principal amount \\ \phantom{ww}$\bullet$ $r =$ interest rate (in decimal form) \\ \phantom{ww}$\bullet$ $t =$ time (in years) \\ \end{minipage}}[/tex]
Given:
- P = $4000
- I = $90
- t = 1 year
Substitute the given values into the simple interest formula and solve for r to find the interest rate:
[tex]\implies 90=4000 \cdot r \cdot 1[/tex]
[tex]\implies 90=4000r[/tex]
[tex]\implies r=\dfrac{90}{4000}[/tex]
[tex]\implies r=0.0225[/tex]
Therefore, the simple interest rate is 2.25%.
Given:
- N = interest
- P = principal
- r = 2.25% = 0.0225
- t = 1 year
Substitute the given values into the formula to create a mathematical model that gives the interest N after 1 year in terms of the amount invested P:
[tex]\implies N=P \cdot 0.0225 \cdot 1[/tex]
[tex]\implies N=0.0225P[/tex]
