For 31, it should be B as HOC is inversely proportional to stability
Similarly you will get ans of 32 as c
Please tell me, how did you compare stability in 31 ?
And compound 2 and 4 of q32
In 31 i compare the stability on the basis of steric hinderanace which causes decrease in stability as you can see.
You know the wedge and line represententa?
In 31 B will have the highest heat of combustion as it is the least stable .For lowest heat of combustion the most stable isomer will be imo D.
For 32 answer should be C.Option 4 will have higher HOC than 4 as cis isomers are less stable than trans isomer.