hi! I couldn’t get why, in the first iteration when we assign p=5, q=5, r=3, s=7, we decide that this does not work? and instead, we go with p7, q=11, r=11, s=13. Greg mentioned smth. about equality, couldn’t catch that
Integers and Primes - GregMat (starts at 1 hour, 6 minutes)
thank you!
It’s p = 2, r = 3, q = 5, and s = 7 in the image though. This gives you B as your answer, but we’ve only tested one number and that always never is sufficient when trying to prove a relationship between two quantities.
Anyhow, another example you could take would be to just swap the values of p and q and thus consequently swapping r and s. This now makes the answer A, which leads you to finally choosing D.
As a side note, prime gaps are extensively studied and the all we have are some bounds, so most questions involving this will automatically be D.
But where can we see answer options? Thank you for your extensive reply!
