.
The publisher of a popular financial periodical has decided to undertake a campaign in an effort to new subscribers.
Market research analysts in this company believe that there is a 1 in 4 chance that the increase in the number of new subscriptions
resulting from this campaign will be between 3000 and 5000. What is the probability
that the increase in the number of new subscriptions resulting from this campaign will be less than 3000 
OR more than 5000?
~~~~~~~~~~~~~~~~~~~~
First, the question was formulated INCORRECTLY.
The correct formulation of the question is THIS:
What is the probability that the increase in the number of new subscriptions resulting from this campaign will be
less than 3000 OR more than 5000?
Solution
According to the condition,
there is a 0.25 = 25% probability that the increase in the number of new subscriptions resulting from this campaign will be between 3000 and 5000
Then the problem asks
What is the probability that the increase in the number of new subscriptions resulting from this campaign will be less than 3000 OR more than 5000?
The answer is that the probability under the question is the COMPLEMENT to that 25% mentioned above, i.e. 75%.
-------------
Solved.
