29. In Mr. Garcia's class, two-thirds of the students are boys. If there are 27 students in the class, how many of them are girls?
Answer: B
There are 9 girls in Mr. Garcia's class.
Given that two-thirds of the students are boys in a class of 27 students, we can determine the number of girls by calculating one-third of the total number of students. This calculation shows that there are 9 girls in the class.
A) 1
This option is incorrect as it does not reflect the total number of girls derived from the problem. If there were only 1 girl, the ratio of boys to girls would not support the fact that two-thirds of the class are boys.
B) 9
This option is correct. To find the number of girls, we calculate the number of boys first: two-thirds of 27 is 18 boys. Therefore, the remaining one-third represents the girls, which is 27 - 18 = 9 girls.
C) 12
This option is incorrect because if there were 12 girls, then the number of boys would be 27 - 12 = 15. This would imply that only about 55% of the class are boys, contradicting the fact that two-thirds are boys.
D) 20
This option is incorrect as it implies there are 20 girls in the class. If this were the case, that would leave only 7 boys, which would not satisfy the condition that two-thirds of the class are boys.
Conclusion
The calculation clearly shows that with two-thirds of the students being boys, only 9 girls can exist in a class of 27 students. All other options fail to meet the ratio of boys to girls required by the problem, confirming that 9 is the only correct answer.