Donald's annual wage is
[tex]23500\text{ pound}[/tex]
He does not have to pay tax first 6400 pound.
He have to pay tax
[tex]23500-6400=17100\text{ pound}[/tex]
At 25% the tax will be 25% of 17100 which is
[tex]\frac{25}{100}\times17100=4275\text{ pound}[/tex]
At 40% the tax will be 40% of 17100 which is
[tex]\frac{40}{100}\times17100=6840pound[/tex]
