Worldnet, Inc., a U.S. corporation, has interest expenses for the tax year of $200,000, no portion of which is directly allocable to identified property under the regulations. World Net's total assets have an adjusted basis/book value of $5,000,000 and a fair market value of $10,000,000. The assets generating U.S. source income have an adjusted basis/book value of $4,000,000 and a fair market value of $6,000,000.
How much of the interest is apportioned to U.S. source income?