Each student at Madison middle school owns three spiral notebooks. Mrs. Campbell wants to calculate the total number of notebooks in the middle school. What variable is needed to calculate the total?
A.
n, the number of spiral notebooks per student
B.
t, the number of teachers who have notebooks
C.
s, the number of students at the school
D.
r, the number of students with red notebooks
C. s, the number of students at the school
Becky and Cathy are sisters. Becky is four years older than Cathy. The following shows how Becky's age, y, changes as Cathy's age, x, changes.
Which equation shows this relationship?
A.
4y = x
B.
y + 4 = x
C.
y = 4x
D.
y = x + 4