Problem
Country
Age
11
We did try and error on all the numbers and went through the numerical order starting from 0.
We got the 1 and 2 from 3, we got 3 and 4 from 7, 7 and 6 from 13,9 and 5 from 14 and 0 and 8 from 8.
So we think in the number 8 envelope the two cards are 0 and 8.