Trevor earned $826 on an account bearing 2.6 percent interest for 7 years

How much money did he invest? (p)

This is a simple interest formula computation.

Given:

Interest = 826

Interest rate = 2.6%

term = 7 years.

The simple interest formula is:

Interest = Principal * Interest rate * term

To solve for the principal:

Principal = Interest / (Interest rate * term)

Principal = 826 / (2.6% * 7)

Principal = 826 / 18.2%

Principal = 4,538.46

To check: Solve for the interest

I = 4,538.46 * 2.6% * 7

I = 117.999 * 7

I = 825.993 rounded up to 826.