Q258 / 270 · NDA 2018 (Phase 2) · Mathematics

Three groups of children contain 3 girls and 1 boy; 2 girls and 2 boys; 1 girl and 3 boys. One child is selected at random from each group. The probability that the three selected consist of 1 girl and 2 boys is

  • Correct answer
    A
    13/32
  • B
    9/32
  • C
    3/32
  • D
    1/32

Solution

Required probability $\begin{aligned} & =\frac{3}{4} \times \frac{2}{4} \times \frac{3}{4}+\frac{1}{4} \times \frac{2}{4} \times \frac{3}{4}+\frac{1}{4} \times \frac{2}{4} \times \frac{1}{4} \\ & =\frac{26}{64}=\frac{13}{32} \end{aligned}$

Hence, the correct answer is option: 'A'.

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