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In a class there are 10 boys and 8 girls...

In a class there are 10 boys and 8 girls. The teacher wants to select either a boy or a girl to represent the class in a function. The number of ways the teacher can make this selection.

A

18

B

80

C

`10^(8)`

D

`8^(10)`

Text Solution

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The correct Answer is:
To solve the problem of selecting either a boy or a girl from a class of 10 boys and 8 girls, we can follow these steps: ### Step-by-Step Solution: 1. **Identify the Total Number of Students**: - There are 10 boys and 8 girls in the class. - Total number of students = Number of boys + Number of girls = 10 + 8 = 18. 2. **Understand the Selection Requirement**: - The teacher wants to select either one boy or one girl to represent the class. - This means we need to select 1 student from the total of 18 students. 3. **Use the Combination Formula**: - The number of ways to select r items from n items is given by the combination formula: \[ \binom{n}{r} = \frac{n!}{r!(n-r)!} \] - In our case, we want to select 1 student (r = 1) from 18 students (n = 18). 4. **Calculate the Combination**: - Substitute n = 18 and r = 1 into the combination formula: \[ \binom{18}{1} = \frac{18!}{1!(18-1)!} = \frac{18!}{1! \cdot 17!} \] - Simplifying this, we find: \[ \binom{18}{1} = \frac{18 \times 17!}{1 \times 17!} = 18 \] 5. **Conclusion**: - Therefore, the total number of ways the teacher can select either a boy or a girl to represent the class is **18**.

To solve the problem of selecting either a boy or a girl from a class of 10 boys and 8 girls, we can follow these steps: ### Step-by-Step Solution: 1. **Identify the Total Number of Students**: - There are 10 boys and 8 girls in the class. - Total number of students = Number of boys + Number of girls = 10 + 8 = 18. ...
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OBJECTIVE RD SHARMA ENGLISH-PERMUTATIONS AND COMBINATIONS-Chapter Test
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  16. The number of diagonals that can be drawn by joining the vertices of a...

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  19. There are 10 points in a plane, out of these 6 are collinear. If N is ...

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