You might then also want to look at the useful load on a typical C172 and wonder how they managed to go 4 up plus luggage each for a couple of nights.
Especially when you include a sensible fuel load to get from their departure point, across the cairngorms and still have enough for a divert and reserves.
I'd like to know how they got all that in and kept it under the MTOW ??
Perhaps they were all really skinny !!
Regards
UA