Question 1025439
p(a) = .76
p(b) = .46
p(a and b) = .41


p(a or b) = p(a) + p(b) - p(a and b)


that becomes .76 + .46 - .41 which is equal to .81


p(not(a or b)) is equal to 1 - p(a or b) which is equal to 1 - .81 = .19


the probability that neither is available is equal to 1 minus the probability that either is available.