Income tax

Hi tutor, Could you please explain the answer from Illustration 1: Darton Co in TEXT book? In 20x8, Darton Co had taxable profits of $120,000. In the previous year, (20x7) income tax on profits had been estimated as $30,000. The income tax rate is 30%. Calculate tax payable and the charge for 20x8 if the tax due on 20x7 profits was subsequently agreed with the tax authorities as: (a) $35,000 (b) 25,000 So, with (a), the tax charge (SPL) = 120,000 * 30% + (35,000 - 30,000) = 41,000 Tax payable (SFP) = 120,000 *30% = 36,000 with (b), tax charge = 36,000 - (30,000 - 25,000) = 31,000 tax payable = 36,000 But in the TEXT book, they use the same figure for tax charge and liability. Specifically, (a) Tax charge and liability: 41,000 (b) tax charge and liability: 31,000 Thank you in advance.