Mary has invited all her friends and all the students in her class to her birthday party. She invited 27 girls and 15 boys in all. What fraction of the people she invited are girls?
27/42 = 9/14
To find the fraction of the people Mary invited who are girls, we need to divide the number of girls by the total number of people she invited. In this case, she invited 27 girls and 15 boys, so the total number of people invited is 27 + 15 = 42.
So, the fraction of people who are girls is 27/42.
To simplify this fraction, we can find the greatest common divisor (GCD) of the numerator and denominator, which is 3.
Dividing both the numerator and denominator by the GCD, we get: (27/3) / (42/3) = 9/14.
Therefore, the fraction of the people Mary invited who are girls is 9/14.