Class 11

Math

Algebra

Permutations and Combinations

A box contains two white balls, three black balls and four red balls. In how many ways can three balls be drawn from the box if at least one black ball is to be included in the draw

- $64$
- $45$
- $46$
- none of these

No. of ways in which 3 balls can be drawn from the box such that no black ball is included in the draw,

$=9C_{3}−6C_{3}=64$ $ways.$