How do I calculate the nominal interest, if i don't have the real interest rate and inflation rate. And what is the inflation rate formula?

Please give me hand. Thanks

Darla puts her money into a bank account that earns interest. One year later she sees that the account has 6 percent more dollars and that her money will buy 7.5 percent more goods.

This is the answer: The nominal interest rate was 6 percent and the inflation rate was -1.5 percent.