Shane Industries prepared a fixed budget of 60,000 direct labor hours, with estimated overhead costs of $300,000 for variable overhead and $90,000 for fixed overhead. Shane then prepared a flexible budget at 57,000 labor hours. How much is total overhead costs at this level of activity?

a. $285,000

b. $375,000

c. $370,500

d. $390,000

How do I solve this?

Thank you