I have a work sheet, 4 columns., d, e, f, g

I need to write an IF statement that fixes the following problem

Column D will always have a value in it.
IF column E has a value in it, but F, and G, do not, then value in column D*30
IF column F has a value in it, but E and G, do not, then value in column D*30
IF column G has a value in it, but E and F do not, then value in column D*30
IF column E and F has a value in it, but G does not, then value in column D*37
IF column E and G has a value in it, but F does not, then value in column D*37
IF column F and G has a value in it, but E does not, then value in column D*37

Is there anyway to write this formula? My problem is that the values in any
of these columns could be any positive number, or they could be blank. Any
suggestions would be great.

Sincerely,
Chris Lamutt