if |a|=0.8 which is less than 1 and |b|=0.2 which is also less than 1 but |ab|= 1.6 which is greater than 1. so your very first line of the solution is wrong
if you just want a deep study of it then you have must read "garudpurana" a hindu book ... and iam an indian so i had read that... so please if you want a correct ans.. of your question please take look of that book
sir it is true since it has been already proved by the quantum that an atom is approx 99.9% vaccant. and everything is made up of an atom so it is agreed by me