The mean of the numbers obtained by throwing a die having written 1 on three faces, 2 on two faces and 5 on one face is
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 2
The numbers 1, 2 and 5 appear on 3, 2 and 1 faces, so their probabilities are \( \frac{3}{6},\frac{2}{6},\frac{1}{6} \). The mean is
\( \displaystyle E(X)=1\cdot\frac{3}{6}+2\cdot\frac{2}{6}+5\cdot\frac{1}{6} \)
\( \displaystyle =\frac{3+4+5}{6} \)
\( \displaystyle =2 \)
CBSE Applied Mathematics (Class XII):
Probability Distribution
