Annie pays 25% tax, she saves 35% after tax income, she and Susan have the same amount of expense.
so if she makes $100 pre tax income, she will have $75 after tax, she saves 35% of it, which is $26.25, she will have 48.75 to spend, divide that equally between Annie and Susan, each spend $24.375, which is 24.375% of the pretax income, not 20%