Solution:
we are given that
A sub fires 4 torpedoes at a ship. each one has a 25% chance of hitting the ship.
Probability that on each fire ship will get hit=0.25
Probability that on each fire , ship will sink[tex]=1-0.25=075[/tex]
Probability that at least one of the fire will hit the ship[tex]=1- \text{Probability of no hiting}[/tex]
Probability that at least one of the fire will hit the ship[tex]=1-(0.75)^4=0.68359[/tex]
Hence the required probability is 0.68
