There are 12 girls and 9 boys in Mrs. Johnson's classroom. She said that if she randomly selects one student from her classroom the probability that it is a boy is 3/4. Which mistake did Mrs. Johnson make?
A. She divided the number of girls by the total number of students.
B. She divided the number of boys by the total number of students.
C. She divided the number of girls by the number of boys.
D. She divided the number of boys by the number of girls.
9/12 = 3/4
I am confused ms. sue i don't get it what is the answer
is the answer d then?
No.
Which of the answers shows 9 divided by 12?
no it is asking what is the probability not what you are saying . What he did was wrong
The mistake that Mrs. Johnson made was C. She divided the number of girls by the number of boys.
To determine the mistake made by Mrs. Johnson, we need to understand the concept of probability and how it is calculated.
Probability is calculated by dividing the number of desired outcomes by the total number of possible outcomes. In this case, the desired outcome is choosing a boy, and the total number of possible outcomes is the total number of students.
Let's analyze the answer choices one by one:
A. She divided the number of girls by the total number of students.
This is not the mistake Mrs. Johnson made. Dividing the number of girls by the total number of students would give the probability of selecting a girl, not a boy.
B. She divided the number of boys by the total number of students.
This is the correct calculation for determining the probability of selecting a boy. Dividing the number of boys (9) by the total number of students (12 + 9) would give the probability of selecting a boy.
C. She divided the number of girls by the number of boys.
This does not accurately calculate the probability of selecting a boy. The number of girls divided by the number of boys would give the ratio between the number of girls and boys, but it doesn't give the probability.
D. She divided the number of boys by the number of girls.
This does not correctly calculate the probability of selecting a boy. Dividing the number of boys by the number of girls would give the ratio between the number of boys and girls, but it doesn't give the probability.
Therefore, the mistake Mrs. Johnson made is D. She divided the number of boys by the number of girls, instead of dividing the number of boys by the total number of students.