Piano lessons cost 15$. What expressions could he use to find the coast of 5$

Answer 1

"Piano LessonS" cost $15

if 3 lessons cost $15, then one lesson costs 15/3 = $5

C(L) = 3L where L = number of lessons and C is measured in dollars

or

if one Piano Lesson cost $15

then $5 only gets you 1/3 of a Lesson

if the Lesson takes 1 one hour

$5 gets you 1/3 of an hour = 20 minutes