Which is a pair of independent events? a. choosing one calendar date for sports practice and then choosing a back-up date b. choosing one card from a deck and then choosing one card from another deck c. choosing a pen to write with in class and then choosing another to let a friend use d. choosing a first place and then a second place work of art

The correct option is B.

Step-by-step explanation:

Consider the provided statement:

The definition of the Independent Event is: An event is said to be independent if the event is not affected by other events or the event is independent of the previous event.

Now consider the provided options:

Option A. We can choose any date for the sports practice but if we want to choose the backup date then we can not choose the same date.

For example: If we choose 25 Aug for the practice then the backup data must be a different date. That means the event is affected by the previous event. Thus, it is not the correct option.

Option B. Choosing one card from a deck and then choosing one card from another deck. That is the independent event because there is the same probability of choosing one card from any of those decks.  

For example: If we choose one card from the first deck, there are still 52 cards in the second deck.  Choosing one card did not affect the other.

Thus, it is the correct option.

Option C. Choosing a pen to write within the class and then choosing another to let a friend use is not independent because the event is affected by the previous event. Thus, it is not the correct option.

Option D. Choosing the first place and then a second-place work of art is also not independent because you can not select the same person for first and second place. That means the event is affected by the previous event. Thus, it is not the correct option.

Hence, the correct option is B.