Answer:
6
Step-by-step explanation:
The largest factor that is common to all these numbers is 6. That is the number of pencil boxes Lana can fill.
18 = 6×3
24 = 6×4
36 = 6×6
___
Each of her six (6) pencil boxes will have 3 pencils, 4 erasers, and 6 crayons.