In a bank, to save funds for 3 months is at an interest rate of 3.9%, for a period of 3 to 6 months is at an interest rate of 4.6%, from 6 to 9 months is at an interest rate of 5.8% and for a period of 9 to 12 months at is at interest of 6.8%. How much interest will be paid on 
for a period of:
4 months?
10 months?
