Income tax

Hi tutor,

Could you please explain the answer from Illustration 1: Darton Co in TEXT book?

In 20×8, Darton Co had taxable profits of $120,000. In the previous year, (20×7) income tax on profits had been estimated as $30,000. The income tax rate is 30%.

Calculate tax payable and the charge for 20×8 if the tax due on 20×7 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.