Question

When a perfect die is rolled, the probability of getting a face with 4 or 5 points upward is:
A) $\dfrac{1}{3}$
B) $\dfrac{2}{3}$
C) $\dfrac{1}{2}$
D) $\dfrac{1}{4}$

Answer 1

Here, we need to look at the question carefully, according to the question we have been asked the probability of getting a face 4 or 5 upward. Here, the questionnaire is asking the combination of two probabilities one for getting 4 points upwards and another 5 points upward. Apply the general formula for probability and solve.

Complete step by step solution:
Probability is defined as:
$P\left( A \right) = \dfrac{{{\text{Number of Favourable Outcome}}}}{{{\text{Total Number of Favourable Outcomes}}}}$ ;
There are six total number of favorable outcomes and out of the six the outcomes only single time 4 points is there on the dice so; the probability would be:
$P\left( A \right) = \dfrac{1}{6}$;
Similarly, for 5 points the total number of favorable outcomes is six and out of six only single time 5 point is there on the dice so, the probability would be:
$P\left( A \right) = \dfrac{1}{6}$;
Now, in the question we have been asked the probability of getting a face 4 or 5 points upwards, the probability would be:
$P\left( A \right) = \dfrac{1}{6} + \dfrac{1}{6}$;
$\Rightarrow P\left( A \right) = \dfrac{1}{3};$

Final answer option A. Therefore, when a perfect die is rolled, the probability of getting a face with 4 or 5 points upward is $\dfrac{1}{3}$.

Note: The maximum value of probability can be 1 and the minimum probability can only be 0. There is no probability in the world that is greater than 1 or lower than 0. The whole science of quantum mechanics is based on the probability of finding a particle at a particular position.