class 11

Math

Algebra

Permutations and Combinations

There are 3 boxes numbered $B(i=1,2,3)$ each having 10 balls also numbered from 1 to 10. Three balls are selected one from each box. If number on ball selected from $B$ box is $n$ such that $n_{1}<n_{2}<n_{3}$ then the number of ways equal to (A) $._{10}C_{3}$ (B) $._{10}C_{2}$ (C) $2._{10}C_{2}$ (D) $2._{10}C_{3}$