If 70% of all students purchase a cafeteria lunch, and half of all lunch buyers purchase pizza, then 35% of all students purchase pizza. which property of law does this example illustrate?
a. substitution property
b. symmetric property
c. law of syllogism
d. law of detachment

A. Substitution property

The answer above is correct.

The substitution property states that if one variable equals another, the two variables may substitute one another in any equation. The variable "half of all lunch buyers" equals the variable "35% of all students," so the two are interchangeable in the equation involving the percentage of students that purchase pizza.