To solve this question, we can use the concept of averages.
Let's assume the sum of the 5 quantities is "x".
According to the given information, the average of the 5 quantities is 6. Therefore, we can write the equation:
[ \frac{x}{5} = 6 ]
Simplifying this equation, we get:
[ x = 30 ]
We also know that the average of 3 of the quantities is 8. Therefore, the sum of those 3 quantities is:
[ \text{Sum of 3 quantities} = 8 \times 3 = 24 ]
Now, we can find the sum of the remaining 2 quantities by subtracting the sum of the 3 quantities from the total sum:
[ \text{Sum of remaining 2 quantities} = \text{Total sum} - \text{Sum of 3 quantities} = 30 - 24 = 6 ]
To find the average of the remaining two numbers, we divide the sum by 2:
[ \text{Average of remaining two numbers} = \frac{\text{Sum of remaining 2 quantities}}{2} = \frac{6}{2} = 3 ]
Therefore, the average of the remaining two numbers is 3.
The correct answer is option A) 3.