Final answer:
The deductible amount in the scenario is $10,000, as the remaining $5,000 is not permissible for deductions due to being considered unreasonable or a bribe.
Step-by-step explanation:
In the given scenario, the deductible amount is the part of an expense that a company can subtract from its income before it is subject to taxation.
If only $10,000 is allowed as a deduction and the remaining $5,000 is either deemed unreasonable or considered against public policy (such as a bribe), then the deductible amount is restricted to $10,000. Any amount exceeding that which is considered a bribe or unreasonable is not allowed to be deducted.
This principle underlines the importance of adhering to legal and ethical standards when claiming tax deductions.