Question

Let a, b, c be three distinct real numbers, none equal to one. If the vectors $a\^i+\^j+\^k , \^i+b\^j+\^k$ and $\^i+\^j+c\^k$ are coplanar, then $\frac{1}{ 1 − a }+ \frac{1}{ 1 − b} + \frac{1 }{1 − c }$ is equal to

• A. -1
• B. 1
• C. -2
• D. 2

Answer 1

Answer: (B)

1

Answer 2

The correct option is(B): 1