Hi there

I've almost got no hair left trying out formulas for this, hope someone can help!

1. Setting a percentage margin to set the sale value

example

Cell B19 is cost (value is filled in)
Cell B20 is selling price (value not filled in)
Cell B21 is percentage I want to put in to change the B20 value (for example 30% profit margin)

I need to know what needs to go in B21 to for it to show up as a % and what needs to go into B20 for it to automatically fill in the sale price

2. Percentage Margin

example

Cell B19 is cost (value is filled in)
Cell B20 is selling price (value filled in)
Cell B21 is percentage increase in cell B21 (value not filled in)

B21 needs to show up as a % so I can see what the margin in

Thank you for your time