Answer:
The adjusting entry at the end of January:
Debit Unearned revenue: $480
Credit Revenue: $480
Explanation:
When recceived $600 on January 15 from customer, the company must record:
Debit Cash: $600
Credit Unearned revenue: $600
because all lessons are not provided by the company, the company can't recording revenue.
On January 31, the company provided 8 lessons, so the company must recording revenue for these lesson (8x$60=$480) by adjusting entry.