The following events were occurred in Premier Book Company Limited ("Premier Book"): (1) During December 2019, Premier Book recorded revenue when $50,000 books coupons had been sold out for cash of which only $47,000 books have been delivered to the customers. (2) At the end of January 2020, Premier Book paid the cleaning services of $2,000 for December 2019. The cleaning expense was recorded on the payment date. (3) Premier Book paid an amount of $12,000 in December 2019 to rent an apartment for the shareholder's daughter who was away at college. It was reported as December's rent expense in the Premier Book's financial statements. (4) Premier Book purchased a printing machine at $50,000 in September 2019. At the end of December 2019, the accountant adjusted the value of printing machine to market value at $55,000 and recorded a gain of $5,000 Required: For each of the events (1) to (4) described above, (a) identify the relevant accounting principle that has been violated. (4 marks) (b) indicate the effect (with dollar amount) of each of the above error on the financial statement of Premier Book at the end of December 2019 described in the column headings in the table below. Use the following symbols: O = overstated, U = understated = no effect. and NE Liabilities Equity Assets (1) (2) (3) (4) (6 marks)