Răspuns:
A= {1,2,3,...,99,100}
B se include A
{1,2} se include B se include {1,2,...,81}
reunim {1,2} cu submultimile multimii {3,4,5,...,81}
=> 79 de elemente
=> multimea {3,4,5,...,81} are 2⁷⁹ submultimi
=> nr submultimilor B= nr submultimilor multimii {3,4,5,...,81} => 2⁷⁹
