A bag contains 4 blue , 5 red , and 7 green balls .If 4 balls are drawn one by one with replacement , what is the probablity that all are blue??

total = 16 balls
blue = 4 balls
green? = 7 balls
red = 5balls
probablity of blue balls =??4??? =??1??
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? 16? ? ? ?4
ans = 1/4