Answer:
5 months
ROI = 3.75 %
Step-by-step explanation:
Since,
The simple interest formula,
[tex]I=P\times r\times t[/tex]
Where,
P = Principal amount,
r = rate per period ( in decimal )
t = number of periods,
Here, P = 800, r = 9% = 0.09,
If A is the future amount,
We have, A = 830
I = A - P = 830 - 800 = 30
By substituting the values in the above formula,
[tex]30=800\times 0.09\times t[/tex]
[tex]30=72t[/tex]
[tex]\implies t =\frac{30}{72}=\frac{5}{12}[/tex]
Hence, it will take 5 months. ( 1 year = 12 months )
Now,
[tex]\text{Return on investment }=\frac{I}{P}\times 100[/tex]
[tex]=\frac{30}{800}\times 100[/tex]
[tex]=3.75\%[/tex]
