Step-by-step explanation:
To calculate the number of independent events that occur, the product of the probabilities of the individual events occurring must be calculated.
Therefore if A and B are independent events then:
P (A and B) = P (A) • P (B)
The exercise is as follows:

NOTE:
To obtain the product of two fractions, the numerators must be multiplied with each other and the denominators must also be multiplied with each other.