We are setting up virtual shopping tasks on an online survey. In each shopping task, we can only show up to 20 products on the screen. There are 80...

We are setting up virtual shopping tasks on an online survey. In each shopping task, we can only show up to 20 products on the screen. There are 80 products in total

that we want to test. How many shopping tasks do we need to show so that on average, each product is shown 3 times throughout all the shopping tasks?

Assume all

products are selected randomly and have an equal chance of being selected