Together it takes alan and cindy 1 hour 12 minutes to sort recyclable materials. Alone, Alan would require 1 more hour than cindy. How long would it take cindy to do the job alone.

He was paid 23 dollars for each lawn

Where’s the problems ? ?

Period is the time it takes for one “cycle” to complete. in the parent sine function, period is 2*pi since sin(0) = 0, sin(pi/2) = 1, sin(pi) = 0, sin(3pi/2) = -1, and sin(2pi) = 0. at that point, the sequence repeats itself. i’m not sure if your graph is similar to the sine function since you didn’t provide a picture, but you can find the period by looking at a graph.