Help with maths problem please

[Hagane00]

I'll explain it, the lady most likely prefers short half hour appointments instead of longer ones, therefore she makes it more expensive per half hour, the longer you stay.

There was a woman advertising recently:
1 hr =160
Every additional hr = 600
So, she doesnt like doing 2 hour appointments, but if your willing to pay almost quadruple the price for the second hour, she'll stomach it

The ladies price themselves the way they want to price it and to get the appointments they prefer