Answer:
10%
Step-by-step explanation:
If 40% failed chemistry then 60% passed chemistry.
If 19% failed both chemistry and physics, and 25% failed physics, then 6% passed chemistry and failed physics.
If we let p' represent failing physics and c represent passing chemistry, then ...
P(p'|c) = P(p'c)/P(c)
P(p'|c) = 6%/60% = 0.10 = 10%
If the randomly chosen student passed chemistry, the probability is 10% that he failed physics.
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Your answer is correct.
