BPP text book answer seems wrong to me. Your thoughts?

There is a question in the question bank at the end which I think the answer bank then has wrong. It’s to do with Josie’s Gift aid donation. In my working I extended the basic rate by the Gross gift aid donation, but the books answer doesn’t appear to have done that, and only considered it for adjusted net income when calculating the Personal Allowance.

Here’s the question –

Josie Selby (age 47) received the following income in 2010/11.
Josie
Salary (gross) 100,000
PAYE tax deducted 33,000
Dividends (amount received) 2,538
Bank deposit interest (amount received) 760
Building society interest (amount received) 4,200

Josie made a gift aid donation of £1,600 in December 2010.

Required
Compute the tax payable by Josie Selby for 2010/11.

There answer for non-savings income is then –

Non-savings income
£37,400 × 20% 7,480
£59,635 × 40% 23,854

Surely there should be an extension of £2,000 to the 20% rate for the Grossed up Gift aid donation? So the non-savings income section should look like this

£37,400 x 20% = 7480
£2,000 x 20% = 400
£57,635 x 40% = 23,054

Any thoughts would be most welcome.