Thread: Calcuating on two conditions

Hi, I am developing an invoice and I am stumped with one question -

I am able to create a flowchart, but not this one - but would love to get help from you.

The question is - The first 20 minutes, the service will cost 150 dollars, and 50 dollars for each 20 minutes afterward. Now the flow chart works like this way -

Let's say input is a x

if input is a X,
X equal or less 20 minutes = 150 dollars
OR
X is more than 20 minutes = 150 + ((x-20) (i'm lost in this formula)

If you put 50 minutes - you will pay 150 dollars for first 20 minutes, and there are two 20 minutes intervals - which comes to 100 dollars. 150
+ 100 = 250 dollars.

If you need my MS Excel sheet to get an idea, feel free to email me and I will send you the file.

Thank you in advance for any help!

Shani