Just took a practice test and the question was:

"When do young people are sent their NI number?"

I think you mean

"At what age are young people sent their National Insurance Number?"

Also, there are EIGHT UK BANK HOLIDAYS, not 4.  Your sample test marked me incorrect for replying 8.

http://www.direct.gov.uk/en/Governmentcitizensandrights/LivingintheUK/DG_073741

Hi,

Thank you for your kind effort to highlight grammatical errors. It is much appreciated and will certainly be fixed.

With regards to Bank holidays, I'll refer you to official study material:

There are four ‘Bank Holidays’ and four other public holidays a year (most people call all these holidays Bank Holidays).

http://www.lifeintheunitedkingdomtest.co.uk/?page_id=8

Regards,

E Fidan
Administrator