There are 3 Indians and 3 Chinese in a group of 6 people. How many sub...
No. of sub groups such that every sub group has at least one Indian
Alternate method
Sub groups containing only Indians =
View all questions of this test
There are 3 Indians and 3 Chinese in a group of 6 people. How many sub...
Problem:
There are 3 Indians and 3 Chinese in a group of 6 people. How many subgroups of this group can we choose so that every subgroup has at least one Indian?
Solution:
To solve this problem, we can use the concept of inclusion-exclusion principle.
Inclusion-Exclusion Principle:
The inclusion-exclusion principle is a technique used in combinatorics to count the number of elements in the union of several sets.
Step 1: Total number of subgroups:
The total number of subgroups that can be formed from a group of 6 people is given by 2^6 - 1 = 63, where 2^6 represents the number of possible combinations and 1 is subtracted to exclude the empty subgroup.
Step 2: Subgroups without any Indian:
To find the number of subgroups without any Indian, we need to choose all the people from the Chinese group. Since there are 3 Chinese people, the number of subgroups without any Indian is given by 2^3 - 1 = 7, where 2^3 represents the number of possible combinations of Chinese people and 1 is subtracted to exclude the empty subgroup.
Step 3: Subgroups with at least one Indian:
To find the number of subgroups with at least one Indian, we subtract the number of subgroups without any Indian from the total number of subgroups.
Number of subgroups with at least one Indian = Total number of subgroups - Subgroups without any Indian
= 63 - 7
= 56
Therefore, the correct answer is option A) 56.