We know that, HCF of two prime numbers is 1.
Product of HCF and LCM = 1 x 319 = 319.
Remember that, Product of two number = Product of their HCF and LCM
pq = 319
Now, co-primes with product 319 are (1,319) and (29,11)
Since p > q, p = 29 and q = 11
Then 3q - p = 3 - 29 = 4.