The resulting weight (mass if you are new or anal) and the resulting lever arm are correctly calculated. What’s the issue? As said above the units should be in.lbs and not in/lbs…but hey ho.
you could very well have it weighed twice
2 weighs would have cost £1000 and I would not have learnt anything, and neither would the 1200 pilots who read EuroGA every day 
should be in.lbs and not in/lbs
I think that a value produced by a multiplication of two values of different units is correctly described with the hyphen but sure this can be debated. The / would be wrong because that is a division.
