Answer:
Therefore the required probability is 
Step-by-step explanation:
The probability of success is 
The number of trial = 4
X= the items survive out of 4
p =the probability of success and q = the probability failure.
p=
and 



Therefore the required probability is 
Answer:
92.5% before discount 100% after discount is 92.5%
.5 * .5 is .25 just multiply twice since .5 is squared ( .5 is the same as 1/2)
Glad to help:)