A box contains two white balls, three black balls and four red balls. The number of ways in which three balls can be drawn from the box if atleast one black ball is to be included in the draw, is

Question

Infinity Learn · Accepted Answer

The number of ways of selecting $$3$$ balls out of total $$9$$ (2$$ white, $$3$$ black, $$4$$ red $$balls) is  $$9C3i$$.e., $$9$$×$$8$$×$$76=84The$$ number of ways of selecting $$3$$ balls out of $$non-black$$ six balls is  $$6C3i$$.e., $$6$$×$$8$$×$$43$$×$$2$$×$$1=20Therefore$$, the number of ways of selecting $$3$$ balls out of $$9$$ balls so as to include atleast one black ball $$=$$ $$84$$ – $$20$$ $$=$$ $$64$$.

A box contains two white balls, three black balls and four red balls. The number of ways in which three balls can be drawn from the box if atleast one black ball is to be included in the draw, is

Remember concepts with our Masterclasses.

Ready to Test Your Skills?

free study material