From a group of 10 men and 8 women, the number of ways of forming a committee of 8 members with not more…

From a group of 10 men and 8 women, the number of ways of forming a committee of 8 members with not more than 5 men and not less than 5 women is
  1. 8061
  2. 8060
  3. 20997
  4. 20952

Solution

From group of 10 men and 8 women committee of 8 members with not more than 5 men and not less than 5 women is formed in following ways. Case I. If 3 men and 5 men we selected number of ways $={ }^{10} C_3 \times{ }^8 C_5$ $ =\frac{10 \times 9 \times 8}{3 \times 2} \times \frac{8 \times 7 \times 6 \times 5 \times 4}{5 \times 4 \times 3 \times 2 \times 1}=6720 $ Case II. If 2 men and 6 women are selected Number of ways $={ }^{10} C_2 \times{ }^8 C_6$ $ =\frac{10 \times 9}{2} \times \frac{8 \times 7 \times 6 \times 5 \times 4 \times 3}{6 \times 5 \times 4 \times 3 \times 2}=1260 $ Case III. If 1 man and 7 women are selected number of ways $={ }^{10} C_1 \times{ }^8 C_7=10 \times 8=80$ Case IV. If 0 men and 8 women are selected number of ways $={ }^{10} C_0 \times{ }^8 C_8=1$ total number of required ways $ =6720+1260+80+1=8061 $

Asked in: AP EAMCET 2018 (23 Apr Shift 1)

Practice more Permutation Combination questions on Aicharya