The system of linear equations
x + 2y + z = 4, 2x + 4y + 2z = 8 and 3x + 6y + 3z = 10 has
1
a unique solution
2
infinite many solutions
3
no solution
4
exactly three solutions
The system of linear equations
x + 2y + z = 4, 2x + 4y + 2z = 8 and 3x + 6y + 3z = 10 has