1a. A loan of $10,000 is repaid by 20 level installments at the end of every 6 months. The nominal rate of interest is 8%, convertible half yearly. Find the total amount of interest payment made over the 10-year period.

1b. A sum of $20,000 is used to buy a deferred perpetuity-due that pays $2,100 every year for the first 5 years and $1,000 per year thereafter. If the annual eective rate is 6%, find the deferred period.