A committee of 7 members is to be formed from a group of 8 boys and 4 girls. In how many ways can the committee be formed if at least one girl must be included?
784
660
485
820
To calculate the number of ways the committee can be formed from a group of 8 boys and 4 girls, with at least one girl included, we can use the principle of inclusion-exclusion.
First, we calculate the total number of ways to form a committee of 7 members from the total group of 12 students (8 boys + 4 girls). This can be calculated using the combination formula:
Next, we calculate the number of ways to form a committe only, which is:
Since we want to include at least one girl in the committee, we subtract the number of committees consisting only of boys from the total number of committees:
792 - 8 = 784
Therefore, there are 784 ways to form a committee of 7 members from a group of 8 boys and 4 girls, where at least one girl must be included.
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