S1: False
Ex A=[0,1) (set of all real no. between 0 and 1)
B=N (Set of all natural numbers)
here A∩B is an empty set which is finite
S2:False
Because a hard problem can be a subset of an easy problem and not reducible to easy problem
Ex A=$A_{TM}$ (Turing recognizable but not decidable language i.e. Recursive Enumerable languages)
B=$ \sum^*$
B is decidadle
A is a subset of B
but A is not reducible to B