Answer: 84 tickets
Explanation:
We are told the ratio of the number of tickets Mark collected to the number of tickets Julia collected is 4:3
(1)
In addition, we are told Julia collected 36 tickets:
(2)
Substituting (2) in (1):
(3)
Isolating
:
(4)
Adding Mark's tickets to Julia's:
Therefore, both collected 84 tickets.