Question

Last month, Raul bought 6 used books for $7.50. This month he bought 8 used books for $10.00. What is the constant of proportionality between the cost and the number of books bought?
A. 0.75
B. 1.25
C. 2
D. 2.5

Answer 1

each book cost 1.25

divide

7.50÷6= 1.25

10÷8= 1.25

this is the proportion