I'm a bit stumped on this one. Assuming I have the following cells:

A1: original deposit

A2: the interest rate (%)

A3: the duration in days which the interest rates applied to

A4: days invested

How can I calculate the total return (including the original deposit)?

For example, if the interest rate per 7 days is 3%, and I want to find the total return after 30 days, the cells would look like:

A1: $100

A2: 3%

A3: 7

A4: 30

I appreciate your help