Soldato
Whatever else needs to be said, it's fair to state that @ianh has, here, nailed the phenomena highlighted in the OPMy mates wife, university degree in something non-tech (maybe art or similar) wouldn't believe us when we said 50% and 1/3 were the same when doing a maths problem ie 50 is 1/3 of 150 and 100 + 50% is 150 therefore 50% and 1/3 were the same if you think about it mathematically (I think we were splitting a bill between the 3 of us).