the sum of the ages of Jessica, her mother, and her grandmother is 100 years. the grandmother is twice as old as the mother. Jessica's mother is 28 years older than Jessica. how old is the grandmother?

At the beginning of year 1, carlos invests $600 at an annual compound interest rate of 4%. he makes no deposits to or withdrawals from the account. which explicit formula can be used to find the account's balance at the beginning of year 5? what is, the balance?