In a group of 84 kids 3/7 brought their lunches. This means that the number of kids that bought their lunches will be 3/7 ×total number of kids
= 3/7 × 84 = 36 kids
Of those who bought their lunches 9 got a slice of pizza. This means that 9 kids out of 36 got a slice of pizza.
Fraction of the students who bought their lunches and got a slice of pizza will be the number of students who bought their lunches and got a slice of pizza / the total number of students that bought their lunch. This becomes
