Question 404520
1)
no. of ways to arrange 5 people on 3 groups = 5C2 * 3C2 * 1C1 / 2! = 15  

here two groups has 2 people each and order of the grouping doesn't matter.




2)
no. of ways to make a group of 4 people from 11= 11C4

no. of ways to make a group of 3 people from remaining 7 = 7C3

 
no. of ways to make a group of 2 people from remaining 4 = 4C2


no. of ways to make a group of 2 people from remaining 2 = 2C2

and here 2 groups of 2 people and  order of group doesn't matter 

no. of ways to arrange 11 people on 4 groups = 11C4 * 7C3 * 4C2 * 2C2 /2!


= 34650


try to understand the concept and solve it yourself....