In a particular school assembly of 120 students, there are 40 first graders, 20 of which are girls. If one student is chosen at random, what is the probability that the chosen student vill not be a first grade girl?
Q. In a particular school assembly of 120 students, there are 40 first graders, 20 of which are girls. If one student is chosen at random, what is the probability that the chosen student vill not be a first grade girl?
Determine Total First Grade Girls: First, we need to determine the total number of first grade girls in the assembly.There are 40 first graders and half of them are girls, so there are 20 first grade girls.
Calculate Students Not First Grade Girls: Next, we calculate the number of students who are not first grade girls. Since there are 120 students in total and 20 of them are first grade girls, the number of students who are not first grade girls is 120−20=100.
Find Probability: Now, we find the probability that the chosen student will not be a first grade girl.The probability is the number of students who are not first grade girls divided by the total number of students.So, the probability is 120100.
Simplify Fraction: We can simplify the fraction120100 by dividing both the numerator and the denominator by their greatest common divisor, which is 20. 100÷20=5 and 120÷20=6. So, the simplified fraction is 65.
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