1 Answers

Option 3 : I and IV only

Concept:

If a problem A is polynomial time reducible to problem B. So, B is at least as hard as A.

Explanation:

Here, L1 is polynomial time reducible to L2, L2 is at least as hard as L1.

L3 is polynomial time reducible to L2

L2 is polynomial time reducible to L4.

Option 1:

if L4 ∈ P, then L2 ∈ P

L2 is polynomial time reducible to L4. L4 belongs to P type problem then L2 is also P type problem. So, it is true.

Option 2:

if L1 ∈ P or L3 ∈ P, then L2 ∈ P

If L1 belongs to P or L3 belongs to P, then L2 belongs to P. This is not true because L1, L3 is a polynomial time reducible to L2 not L2 is polynomial time reducible to L1.

Option 3:

L1 ∈ P, if and only if L3 ∈ P

L1 belongs to P, if and only if L3 belongs P. This is false because L3 is polynomial time reducible to L2 not L1.

Option 4:

if L4 ∈ P, then L1 ∈ P and L3 ∈ P

This statement is true because we know that L1 is polynomial time reducible to L2 and L3 is polynomial time reducible to L­2 and L2 is polynomial reducible to L4 so L1 and L2 is polynomial time reducible to L4.
5 views

Related Questions