can anyone help please.

i am a real novice with excel and have been asked to set up a spreadsheet to show what percentages of a starting figure is being spent on materials, labour and then what the final figure remaining is as a percentage

example

starting amount £5000.00 minus £1250.00 materials, what percentage is being spent on materials.

Then labour £2300.00, what percentage of the £5000.00 is this

finally the overall percentage earned after the labour charge and material charges have been deducted from the £5000.00

i really hope someone can help as I really have no idea how to do this