Counting Principle

Find the number of ways in which 4 algebra, 5 geometry and 2 chemistry books can be placed on a shelf so that the arrangement begins and ends with a chemistry book?

• 4!

• 5!

• 9!

• 11!

• 100

• 112

• 130

• 135

• 160

In how many ways, can 5 girls and 3 boys be seated around a table if two boys are together?

How many different 9-letter words can be formed by using the letters of the word "KATAMARAN"?

In how many ways can 2 blue, 3 red and 5 white tumblers all identical, be arranged on a rope?

• 7!

• 2!3!5!

• 10!

• 3!10!

• 2!8!

        By using the digits of the number 6003888, how many different 7-digit numbers can be written?

2 yellow, 3 blue and 4 red balls will be arranged on a line (all balls have different sizes). In how many ways can this be done, if the blue balls must be side by side?

• 7!

• 105

• 630

4 couples will sit around a round table so that each couple (husband and wife) will be side by side. In how many ways can this be done?

         In how many different ways may 2 boys and 2 girls be selected from 8 boys and 4 girls and arranged in a line?

• 168

• 672

• 3024

• 4032

• 6234

In how many ways can 4 boys and 4 girls be seated around a circular table if children of the same gender must not sit next to each other?