Answer:
75% of the progeny contains purple flower in F2 generation.
Explanation:
The cross between the purple and white flower can be done by the following ways:
( Parents)  PP (purple flower)   ×  pp (white flower)
(Gametes) Â Â P Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â p
F1 genereation       Pp (purple flower)
Selfing of F1 genereation :  Pp   ×   Pp
Progeny of F2 genereation are: PP (purple flower), Pp and Pp( purple flower) and pp (white flower).
The phenotype ration of purple to the white flower is 3:1 or 75% of total progeny is purple flowered.
Thus, the answer is 75%