Baffled girlfriend gets the answer to a riddle wrong THREE times before the penny finally drops - how long does it take you?

This is the hilarious moment a baffled girlfriend gets the answer to a simple riddle wrong three times before the penny finally dropped.

The woman, from Chelmsford, Essex, was asked: 'If the big brother is four years old and his little brother is half his age (two years old), how old will the younger brother be if the older brother is 100?' 

The perplexed girlfriend is certain the answer is 50 and can't understand why her boyfriend keeps telling her she's wrong.  

She gets increasingly frustrated and asks: 'Why isn't it 50?!' 

'You said the little brother is half the big brother's age. So when the big brother is 100, he's going to be half of 100 - which is 50.

The boyfriend then guides her through the question for a third, and final, time.

She still doesn't get it so her partner finally gives in and outright says 'It's 98'.

Hilariously, his girlfriend tells him he 'must've got it wrong' because that doesn't add up.

After two whole minutes the riddle is spelled out for her and the penny finally drops. The video ends with her letting off an embarrassed giggle.