xavier , yvonne , and zelda each try independently to solve a problem . if their individual probabilities for success are 1 / 4 , 2 / 3 and 5 / 8 , respectively , what is the probability that xavier and yvonne , but not zelda , will solve the problem ?
n0 = 1.0
n1 = 4.0
n2 = 2.0
n3 = 3.0
n4 = 5.0
n5 = 8.0
t0 = n0 / n1
t1 = n2 / n3
t2 = n4 / n5
t3 = t0 * t1
t4 = 1.0 - t2
answer = t3 * t4
print(answer)