From now on learn mathematics with the puzzle, you can learn something about it here
so let's go

![logicalmathematical.png](https://cdn.steemitimages.com/DQmb3bcY2e8gQCrS2GVtDBUbuVPzJJC1SPLxAQmuwnEv5gW/logicalmathematical.png)
[image source](http://www.pics4learning.com/details.php?img=logicalmathematical.png)
given that

Mango + mango + mango = 30

Mango + banana + banana = 18

Banana-2 litchi = 2

Litchi + mango + banana = ???


The answers to this question may be known to many, and you also give the right answer to your correct answer
i hope  give me your correct answer