Answer:
It will take 3.2 years for his money to grow to $950.
Step-by-step explanation:
This is a simple interest problem.
The simple interest formula is given by:
[tex]E = P*I*t[/tex]
In which E are the earnings, P is the principal(the initial amount of money), I is the interest rate(yearly, as a decimal) and t is the time.
After t years, the total amount of money is:
[tex]T = E + P[/tex].
John deposited $800 in a bank
This means that [tex]P = 800[/tex]
5% interest per year.
This means that [tex]I = 0.05[/tex]
How many years it will take for his money to grow to $950?
We have to find t for which T = 950. So
[tex]T = E + P[/tex]
[tex]950 = E + 800[/tex]
[tex]E = 150[/tex]
And
[tex]E = P*I*t[/tex]
[tex]150 = 950*0.05*t[/tex]
[tex]t = \frac{150}{950*0.05}[/tex]
[tex]t = 3.2[/tex]
It will take 3.2 years for his money to grow to $950.
