4 IF formulas for 1 result

I have 4 cells per row, only one will have a value of 1, the others will remain empty.

Each cell needs to return a different value in the formula cell (eg. cell D2 would return 3, E2 would return 7.5, F2 would return 6 and G2 would return 3). Depending on which cell had the value of 1 would determine the result in the formula.

I want to write IF D2 is 1, return 3, IF E2 is 1, return 7.5, IF F2 is 1, return 6 and IF G2 is 1, return 3 but if none contain 1, return as 0.

I'm most grateful for your help.