Classic PET .... LEMALLIN is absolutely right, for some of these PET/PSR questions VERY accurate wiz wheel work is required ....

I get O=104 kts, H=123.5kts ....... which gives an answer of 97.7nm

Be careful - these are 4 point questions .... or 5% of the Exam!

Final thought - the best way to mark the wind is with a FINE soluble felt tip pen - you get a very accurate 'dot' for the wind ....