How to calculate fuel burn in litres per H:MM

My head has gone on what I thought should be easy to work out, but I'm not getting anywhere with it.
I have attached a sample worksheet with the hour and Litres columns formatted as they are in the original.
I'm not sure how to format the cell where I want the answer to be. I would like the answer to show in one cell (I've split the formula up in my sample to try and see what I was getting wrong)
I would like to work out, how many litres of fuel are used each hour, but it isn't working out correctly so can someone help me with my formula please?
Thank you

In E25 use:
=SUM(B5:B20)*24 and format as General

In F25 use:
=D4/E25 and format as General

You are quite welcome.