Question

If $8C_{r} =^{8} ⥂ C_{r + 2}$, then the value of $rC_{2}$ is.

• A. 8
• B. 3
• C. 5
• D. 2

Answer 1

Answer: (B)

3

Answer 2

$8C_{r} =^{8} ⥂ C_{r + 2} \Rightarrow 8 - r = r + 2 \Rightarrow r = 3$

Hence $3C_{2} = 3$.