On January 2, 20X1, Lava, Inc., purchased a patent for a new consumer product for $90,000. At the time of purchase, the patent was valid for 15 years; however, its useful life was estimated to be only 10 years due to the product’s competitive nature. On December 31, 20X4, the product was permanently withdrawn from sale under governmental order because of a potential health hazard in the product.

Required:

What should the total charge against income on this patent be in 20X4?