4. Investor A deposits $100 into an account that earns simple interest at a rate of 10% per annum. Investor B makes two deposits of $50 each into an account that earns compound interest at an annual effective rate of 10%. B's first deposit occurs n years after A's deposit. B's second deposit occurs 2n years after A's deposit. The balances in the two accounts are equal 10 years after Investor A's deposit. What is the value of n