A Co. Ltd. has Authorised Capital of $ 50,00,000 divided into 1,00,000 Equity Shares of $. 50 each. The Company issued for subscription 50,000 Shares at a premium of $. 10 each. The entire issue was underwritten as follows: X-30,000 Shares (Firm underwriting -5,000 Shares) Y-15,000 Shares (Firm underwriting -2,000 Shares) Z- 5,000 Shares (Firm underwriting -1,000 Shares) Out of the total issue 45,000 Shares including firm underwriting were subscribed. The following were the marked forms: X-16,000 Shares: Y- 10,000 Shares: Z-4,000 Shares. Calculate the liability of each underwriter assuming (a) shares underwritten are treated as marked application. (b) Shares underwritten are treated as unmarked applications.