Let's use j to represent Jiri's age.
If Pamela is 6 years younger that Jiri, her age can be represented by j - 6.
Since the sum of their ages is 64, we can setup the equation j + (j - 6) = 64.
Simplifying on the left, we have 2j - 6 = 64.
Adding 6 to both sides, we have 2j = 70.
Dividing both sides by 2, we have j = 35.
So Jiri is 35 years old and Pamela is 6 years younger or 29 years old.