It takes 18 doodads to make 5 widgets. It takes 11 widgets to make 4 thingamabobs. How many doodads does it take to make 80 thingamabobs?
Since $80=20 \cdot 4$, then to make $80=20 \cdot 4$ thingamabobs, it takes $20 \cdot 11=220$ widgets.

Since $220=44 \cdot 5$, then to make $220=44 \cdot 5$ widgets, it takes $44 \cdot 18=792$ doodads.

Therefore, to make 80 thingamabobs, it takes 792 doodads.

ANSWER: 792