5 Fruits and 5 vegetables or is it 5 fruits and vegetables?

5 Fruits and 5 vegetables=10 the other is only 5

Either is correct depending on what you intend to communicate.

"5 Fruits and 5 vegetables" would indicate 10 total pieces, half being fruits and the other half being vegetables.

"5 fruits and vegetables" would indicate 5 total pieces and we don't know the exact mix.

You generally want to be concise if possible. When there is one adjective that effects multiple nouns, you only need to list the adjective once. That means yes, "5 fruits and vegetables" is more correct. The other is valid-ish, but it would definitely stop someone in their tracks hearing or reading that; and they wont be thinking highly of you or following the point you are trying to make in the meantime, either.