Average marks obtained by A, B and C is 78. Average marks obtained by A and B is 81 and average marks obtained by B and C is 67. What is the mark obtained by B?
1
31
2
54
3
62
4
64
Average marks obtained by A, B and C is 78. Average marks obtained by A and B is 81 and average marks obtained by B and C is 67. What is the mark obtained by B?