Let a, b and c be the distinct non-negative numbers. If the vectors aî + aĵ + ck̂, î + k̂, cî + cĵ + bk̂ lie on a plane, then which one of the following is correct?
1
c is the arithmetic mean of a and b
2
c is the geometric mean of a and b
3
c is the harmonic mean of a and b
4
c is equal to zero
5
Question Not Attempted