PCAT Quantitative Reasoning – Probability of Random Number Selection
 by
 Apr 19, 2018
 PCAT Question of the Day
When randomly selecting two numbers between 1 and 100, what is the probability that both will be a multiple of 4 or neither will be a multiple of 4? The same number can be chosen twice.
A. 3/16
B. 5/16
C. 3/8
D. 5/8
Click for Explanation
D is correct. First, let’s identify the probability of selecting two multiples of 4 in a row. The number of multiples of four (4, 8, 12, etc.) is equal to:
Recall that the same number can be selected twice! The probability of both events occurring is equal to the product of their probabilities:
Now let’s determine the probability of neither being a multiple of 4:
The probability of the first situation occurring or the second situation occurring is the sum of their probabilities:
Search the Blog
Free Consultation
Interested in our Online MCAT Course or one of our OneonOne MCAT Tutoring packages? Set up a free consultation with one of our experienced Academic Managers!
Schedule NowPopular Posts

MCAT Blog How to Review MCAT FullLengths
Free MCAT Practice Account
Need great MCAT practice?Get the most representative MCAT practice possible when you sign up for our free MCAT Account, which includes a halflength diagnostic exam and one of our fulllength MCAT practice exams.
Learn More
Submit a Comment