By referring to the botanical definition:
A nut in botany is a simple dry fruit with one seed (rarely two) in which the ovary wall becomes very hard (stony or woody) at maturity, and where the seed remains attached or fused with the ovary wall. Most nuts come from the pistils with inferiorovaries (see flower) and all are indehiscent (not opening at maturity). True nuts are produced, for example, by some plant families of the order Fagales. This includes chestnuts, acorns and hazelnuts.
Other nuts are not strictly (botanically speaking) a fruit - but rather a seed.
Yes, the walnut is a fruit. in fact, a nut is a type of fruit, however a walnut is not a nut but a different type of fruit called a "drupe".
The fruit commonly mistaken for a nut is the coconut.
No, a banana is not a nut. It is a fruit.
A banana is a fruit.
It is a fruit
No the apple is a fruit, it is not a nut
A nut is a seed or fruit of a tree.
A pecan is classified as a nut.
nut
No, it is a protein.
No, it is a nut.
Mango's are part of the pistachio family of nuts.