For a compound $(A)$ that consists of two cyclobutane rings connected by a single bond and contains one additional double bond, what is the Double Bond Equivalent $(DBE)$ of $(A)$?

What is the molar mass of the third member of a homologous series if the molar mass of the first member is $46 \ g \ mol^{-1}$?

Given below are two statements:
Statement-$I$ : Compound $(X)$, shown below, dissolves in $NaHCO_3$ solution and has two chiral carbon atoms.
Statement-$II$ : Compound $(Y)$, shown below, has two carbons with $sp^3$ hybridization, one carbon with $sp^2$ and one carbon with $sp$ hybridization.
In the light of the above statements, choose the correct answer from the options given below:

Which of the following $C_6H_6$ compounds has a single set of structurally equivalent hydrogen atoms? The structures are labeled $I$ to $V$ as shown in the image.

Which compound contains $1^o, 2^o, 3^o$ and $4^o$ carbon atoms?

The number of secondary carbon atoms present in the following compounds are respectively: