Answer:
50%
Explanation:
This is a case of incoplete dominance of the red allele over the white allele.
Let the red allele be R and the white allele be r.
RR x rr = All Rr, pink flower phenotype.
The pink flower plants are then crossed with white flower plants;
Rr x rr = Rr (pink), Rr (pink), rr (white) and rr (white).
50% or 1/2 of the offspring will be pink flowered while the remaining 50% or 1/2 will be white flowered.
