Question Practice

Qn #1589
Let $T_n$ denote the number of triangles which can be formed by using the vertices of a regular polygon of $n$ sides. If $T_{n+1} - T_{n} = 21$ then $n$ equals
    ❓ Question: Let $T_n$ denote the number of triangles which can... | TANCET Group Studies | Tancet Group Studies