Chemistry - GOC Question with Solution | TestHub

α-carbons of the $\mathrm{C}=\mathrm{C}$ : the $\mathrm{C}{\mathrm{H}}_3$ (3 H) and the two bridgehead carbons (1 H each).

A hyperconjugative structure from a bridgehead C-H would place a double bond at the bridgehead of the small bicyclic ring (Bredt's rule), so the two bridgehead C-H bonds do not count.

Hyperconjugating structures = 3 (from $\mathrm{C}{\mathrm{H}}_3$).