Credit institution RichBank and credit institution SwissBank make two different offers on their saving account options when a deposit of $10,000 is made. RichBank offers a 6% annual interest rate, compounded monthly. SwissBank offers 10% annual interest rate for the first 6 months and an annual x% for the following 6 months. What does the rate x need to be when the gain with SwissBank is $100 higher than with RichBank? Assume the accounts are kept untouched throughout. Please write out the strategy and final result.