Let S₁={(i,j,k): i,j,k∈{1,2,…,10}}, S₂={(i,j): 1≤i<j+2≤10, i,j∈{1,2,…,10}}, S₃={(i,j,k,l): 1≤i<j<k<l, i,j,k,l∈{1,2,…,10}} and S₄={(i,j,k,l): i,j,k,l are distinct elements of {1,2,…,10}}. If the number of elements in Sᵣ is nᵣ, which statements are true?