ABC Ltd had the following transactions in the last two months of its year ended December 31, 2019

Nov 1: Paid Shs 9,500 cash for future newspaper advertising

Nov 2: Paid Shs 21,600 cash for 12 months of insurance through October 31, of the next year

Nov 30: Received Shs 33,000 cash for future services to be provided to a customer

Dec 1: Paid Shs 27,000 cash for a consultant's services to be received over the next three months

Dec 15: Received Shs 76,500 Cash for future services to be provided to a customer

Dec 31: Of the advertising paid for on Nov 1, Shs 9,000 worth is not yet used

Dec 31: Services worth Shs 12,000 are not yet provided to the customer who paid on Nov 30

Dec 31: One third of the consulting services paid for on Dec 1 have been received

Dec 31: The Company has performed Shs 30,000 worth of services that the customer paid for on Dec 15

Required

a) Adjusting entries from the information provided above at the end of the year

b) What is the Objective of a trial balance? Explain three possible errors that may not be detected by the extraction of a trial balance