Question

Consider three boxes, each containing $10$ balls labelled $1,2,....,10$. Suppose one ball is randomly drawn from each of the boxes. Denote by $n_i$, the label of the ball drawn from the $i^{th}$ box, ($i = 1, 2, 3$). Then, the number of ways in which the balls can be chosen such that $n_1 < n_2 < n_3$ is :

• A. 82
• B. 240
• C. 164
• D. 120

Answer 1

Answer: (D)

120

Answer 2

No. of ways = $10C_3 = 120$