Question 1013292
The probability that one only hits is (0.55)(0.05)=0.0275+ (0.45)(0.95)=0.4275 The first term of 0.55*0.05 is the probability the first one hits and the second one doesn't hit.  They are independent, so the probability is multiplied.  The second is just the opposite.
They add up to 0.4550, or 45.5%, which is 91/200.
At least one is 1-probability that both miss.  That is 0.45*0.05=0.0225
That is 2.25% or 2.25 per 100 or 9 per 400 that both miss.  Subtract 9 from 400 and 391/400 is the probability that at least 1 will hit.