Aren't the third and fourth Demorgan's laws the same.(in A but not in B and C)
There are 4 test tubes A, B, C and D. The first test tube (A) dissolves NaCl but not Benzene. The second test tube (B) dissolves alcohol but not water. The third test tube (C) dissolves benzene but not NaCl and the fourth test tube (D) dissolves NaCl but not chloroform. Which of the following test tubes contains organic compound(s) ?