If a student is selected at random from a group of 20 students, 12 of whom are b
Practice Questions
Q1
If a student is selected at random from a group of 20 students, 12 of whom are boys, what is the probability that the student is a girl?
1/5
2/5
3/5
1/2
Questions & Step-by-Step Solutions
If a student is selected at random from a group of 20 students, 12 of whom are boys, what is the probability that the student is a girl?
Step 1: Identify the total number of students in the group. There are 20 students.
Step 2: Identify the number of boys in the group. There are 12 boys.
Step 3: Calculate the number of girls by subtracting the number of boys from the total number of students. This is 20 - 12 = 8 girls.
Step 4: To find the probability of selecting a girl, divide the number of girls by the total number of students. This is 8 girls / 20 total students.
Step 5: Simplify the fraction 8/20. Both numbers can be divided by 4, which gives us 2/5.
Probability Calculation – Understanding how to calculate the probability of an event by determining the ratio of favorable outcomes to total outcomes.
Complementary Counting – Using the total number of students and the number of boys to find the number of girls, demonstrating the concept of complementary counting.
