That’s the answer to your question. The official answer will also say the same thing. Legally, you can put more than one mobile goal in the 20 point zone, but only one of those mobile goals will be considered scored in the 20 point zone. However, if the other mobile goals are touching the large pipe, they count as being in the 10 point zone.
Check the game manual please next time before asking a question. It helps to do that to reduce the number of redundant questions that get posted in the Q&A section.
Yea if by some way you ended up with 2 in the 20 point zone they would count the one with the most cones to be scored in the 20 and the one with less cones if it is touching the big pipe would be in the 10