Answer:
240
Explanation:
Since David has 60 fewer storybooks than Huiling, take the total number of storybooks, which is 460 and minus it by 60.
460-60=400
Now, there are 5 units, 5units=400
1unit=80
Since Jenny has 3 times as many storybooks as David, Jenny has 3 units, 3unit=80x3=240
Tip: Draw a model to help you visualise the question better.