Chef Alfredo made the investment 4 years ago.
To solve this problem, we have to use the formula of simple interest.
Data;
The formula of simple interest is given as
[tex]S.I = \frac{PRT}{100}[/tex]
Let's subtract the principal from the final amount to know the simple interest
[tex]6000-4800=1200[/tex]
Substitute the values into the formula
[tex]s.i=\frac{prt}{100} \\1200=\frac{6000*5*t}{100}\\ 1200*100=6000*5*t\\120000=30000t\\t = 4[/tex]
The time he made that investment was 4 years ago
Learn more on simple interest here;
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