Answer: Pt= 3/256
Step-by-step explanation:
For each round the probability of winning is:
Pw = number of blue dotted ducks/ total number of ducks
Pw= 5/20 ( since the duck is being replaced)
The probability of losing is:
Pl= number of ducks without blue dotted belly/ total number of ducks
Pl = 15/20
Therefore the probability of winning 3 times out of 4 is:
Pt= Pw× Pw×Pw×Pl
Pt= (5×5×5×15)/(20×20×20×20)
Pt= 1875/160000
Pt= 3/256
Goodluck...