Probability questions

1. Out of 10 white, 9 black and 7 red balls, the number of ways in

which a selection of one or more balls can be made is

a. 881

b. 891

c. 879

d. 892

solution-

The white balls can be selected in 10 + 1 = 11 ways.

The black balls can be selected in 9 + 1 =10 ways.

The red balls can be selected in 7 + 1 = 8 ways.

Total number of ways = 11*10*8 = 880

But this includes the case when no ball is selected.

Hence the required number of ways = 880 - 1 = 879

## No comments:

## Post a Comment