Answer:
a.
Oct 1 Cash $240 Dr
Unearned Subscription Revenue $240 Cr
b.
Dec 31 Unearned Subscription Revenue $60 Dr
Subscription Revenue $60 Cr
Step-by-step explanation:
a.
The receipt of $240 upfront in advance from a customer is a liability for the business as the business has received cash for service that is yet to be provided. The business will record this as a debit to the cash account and credit to a liability account of Unearned Service Revenue.
b.
On 31 december, the business has provided magazines for 3 months thus it has earned revenue for 3 months. The revenue for 3 months is,
Revenue per month = 240 / 12 = 20
For 3 months = 20*3 = 60
The business will record this as a credit to the subscription revenue and a debit to the unearned subscription revenue