Question

Out of $10$ white, $9$ black and $7$ red balls, the number of ways in which selection of one or more balls can be made, is:

• A. $881$
• B. $891$
• C. $879$
• D. $892$

Answer 1

Answer: (C)

$879$

Que : $10$ white, $9$ black, $7$ red balls

$\to$ first, you can select from 10 w ball $(10+1)$ choice

$\to$ then, you select from 9 black ball. $(9+1)$ choice

$\to$then, you select from 7 red ball. $(7+1)$ choice

$\to$ putting together total choice $(10+1)(9+1)(7+1)$

$=11\times 10\times 8$

$=880$

$\to$ Here you cannot select none of all ball.

so $=880-1$

$=879$