Problem solving (Show your calculation steps).

 At a football game, $\frac{4}{5}$ of the seats in the lower deck of the stadium were sold. If one-fourth of all the seating in the stadium is located in the lower deck, and if $\frac{2}{3}$ of all the seats in the stadium were sold, what fraction of the unsold seats in the stadium were in the lower deck?

Problem solving (Show your calculation steps).

A department store receives a shipment of 1,000 shirts, for which it pay Tk. 9,000. The store sells the shirts at a price 80% above cost for one month, after which it reduces the price of the shirts to 20% above cost. The store sells 75% of the shirts during the first month and 50% of the remaining shirts afterward. How much gross income did sales of the shirts generate?