We've already had a similar riddle when you had to find hidden words in pictures. Here's another brain teaser for your enjoyment. But what is interesting with this one is that people can't agree on the same answer.
So I will say answer is 15.
But if the numbers of bananas and coconuts in the images really count, then the answer is 14 (1 + 10 +3). So dude in #6 is right.