2. Andrea wants to deposit money into a bank account that earns 4% simple interest. Use the formula to find the amount of money that she should deposit so that she earns $2800 after 3.5 years. Show and explain your work.

There are several important information's that has already been provided in the question. Using these information's the answer to the given question can be easily found. Let us write down the given information's first.

Interest earned = $2800

Rate of Interest = 4%

Time for which the money is kept = 3.5 years

Let us assume the principal amount to be = x

Now we already know

Interest earned = Principal * Rate of Interest * Time

Principal = Interest earned / (Rate of Interest * Time)

= 2800 / (4% * 3.5)

= (2800 * 100) / (4 * 3.5)

= 280000/14

= 20000

So the amount Andrea should deposit is $20000. This is the only method of solving these kind of problems very easily. Hopefully you have got the answer you were looking for.