Question

The mean of the numbers obtained on throwing a die having written 1 on three faces, 2 on two faces, and 5 on 1 face is :

• A. 1
• B. 2
• C. 5
• D. \(\frac{8}{3}\)

Answer 1

The Correct Option is B

To find the mean of numbers obtained by throwing a die with faces numbered as follows: three faces with "1", two faces with "2", and one face with "5", we need to calculate the average. First, let's determine the total sum of the numbers on all faces and then divide it by the total number of faces.

• Total occurrences of the number "1" = 3
• Total occurrences of the number "2" = 2
• Total occurrences of the number "5" = 1

Now, calculate the sum of all numbers:

\[ \text{Sum} = (3 \times 1) + (2 \times 2) + (1 \times 5) \]

\[ = 3 + 4 + 5 \]

\[ = 12 \]

Next, calculate the total number of faces:

\[ \text{Total Faces} = 3 + 2 + 1 = 6 \]

Now, calculate the mean:

\[ \text{Mean} = \frac{\text{Total Sum}}{\text{Total Faces}} = \frac{12}{6} = 2 \]

Thus, the mean of the numbers obtained on throwing the die is 2.