0 votes 0 votes A simple non directed graph contains 21 edges, 3 vertices of degree 4 and the other vertices are of degree 2. then the number of vertices in the graph is ? adarsh shivhare asked Dec 30, 2017 adarsh shivhare 5.6k views answer comment Share Follow See 1 comment See all 1 1 comment reply Ashwin Kulkarni commented Dec 30, 2017 reply Follow Share By handshaking, sum of degree of vertices = 2*E, Let V be the total vertices 3*4 + (V-3)*2 = 2*21 (V-3)*2 = 30 V = 18 0 votes 0 votes Please log in or register to add a comment.