Suppose we have problems P1 and P2. Suppose there is a polynomial-time reduction from P1 to P2. a. What can we say about the existence of an efficient algorithm
for deciding P1 if there is an efficient algorithm deciding P2?

b. Can we say the same thing about an efficient algorithm for
deciding P2 if there is an efficient algorithm deciding P1?

(Here an efficient algorithm is one that runs in polynomial-time
in the size of its input).