Q1 of 68 Page 341

In how many ways can 5 sportsmen be selected from a group of 10?

As there are 10 sportsmen out of which 5 are to be selected.

5 sportsmen can be selected out of 10 in ¹⁰C₅ ways.

Applying ⁿC_r =

We get,

⇒ ¹⁰C₅ =

252 ways

Hence, there are 252 ways of selecting 5 sportsmen from 10 sportsmen.

How many chords can be drawn through 21 points on a circle?

From a class of 25 students, 4 are to be chosen for a competition. In how many ways can this be done?

A bag contains 5 black and 6 red balls. Find the number of ways in which 2 black and 3 red balls can be selected.

Find the number of ways of selecting 9 balls from 6 red balls, 5 while balls and 4 blue balls if each selection consists of 3 balls of each colour.