An examination consists of two papers, Paper 1 and Paper 2. The probability of failing in Paper 1 is 0.3 and that in Paper 2 is 0.2. Given that a student has failed in Paper 2, the probability of failing in Paper 1 is 0.6. The probability of a student failing in both the papers is A. 0.5 B. 0.18 C. 0.12 D. 0.06

0.5
0.18
0.12
0.06

The correct answer is $\boxed{\text{B) 0.18}}$.

The probability of a student failing in both the papers is the probability of failing in Paper 1 and failing in Paper 2, given that the student has failed in Paper 2. This can be calculated as follows:

$$P(\text{fail in both}) = P(\text{fail in 1 and 2}) = P(\text{fail in 1}) \cdot P(\text{fail in 2} | \text{fail in 1})$$

We are given that $P(\text{fail in 1}) = 0.3$ and $P(\text{fail in 2} | \text{fail in 1}) = 0.6$. Substituting these values into the equation, we get:

$$P(\text{fail in both}) = 0.3 \cdot 0.6 = 0.18$$

Option A is incorrect because it is the probability of failing in Paper 1, not the probability of failing in both papers. Option C is incorrect because it is the probability of failing in Paper 2, not the probability of failing in both papers. Option D is incorrect because it is the probability of failing in Paper 1, given that the student has failed in Paper 2, not the probability of failing in both papers.

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