Final answer:
The book value of the equipment at the end of the second year is $60,000.
Step-by-step explanation:
The book value of the equipment at the end of the second year can be calculated by subtracting the accumulated depreciation from the original cost.
Accumulated depreciation after two years: $20,000 x 2 = $40,000
Book value = Original cost - Accumulated depreciation = $100,000 - $40,000 = $60,000
Therefore, the book value of the equipment at the end of the second year is $60,000.