Answer:
3/13
Step-by-step explanation:
K_ gives blue flower pigment
kk gives white flower
The presence of D, either as K_DD or K_Dd results in white flower
Crossing 2 plants with KkDd genotype:
KkDd x KkDd
Offspring:
KKD_ = 9/16 white flower
KKdd = 3/16 blue flower
kkDD = 3/16 white flower
kkdd = 1/16 white flower
Hence, the ratio of blue to white flower would be 3:13
See the attached image for the Punnet's square