Single Taxpayer simply invests for a living and has no salary. During 2018 Single has (1) gain of $10,000 from the sale of stock held for less than 1 year; (2) a gain of $15,000 on a collectible held for 2 years; and (3) a gain of $20,000 on stock held for 15 months. Disregarding any deductions (including the standard deduction and personal exemption), what is Singles tax liability for 2018?