Permutation in equation!

Positive integers $$n_1<n_2<n_3<n_4<n_5$$ are such that $$n_1+n_2+n_3+n_4+n_5=20.$$ Find the number of distinct tuples of $$\left(n_1,n_2,n_3,n_4,n_5\right)$$.

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