Each question is 7 points and total are 21 points. Please show your detailed work to get full credits. 1. Bank X's total assets is $170 million with a duration of 8 years, and its liabilities is $140 million with a duration of 4 years. a) what is duration gap for the bank? b) If interest rate decrease from current level of 8% to 7%, how much bank's net worth changes in $