Great question, it is always good to ask away and get rid of any doubts that you may be having.
Since we are given 3 values with 1 variable, and since this is a ratio problem. Then we can use the Rule of Three technique in order to solve this problem. The Rule of Three technique is shown in the picture attached below.
3 oranges ⇒ 5 picks
12 oranges ⇒ x picks
As we can see from the calculation above there are a total of 20 picks
I hope this answered your question. If you have any more questions feel free to ask away at Brainly.