let poundCrab = 3.8

let pountLobster = 6.8

​

let crab_rate rate = poundCrab * rate

let lobster_rate rate = pountLobster * rate

​

let convert_func (rate) = 

    crab_rate rate , lobster_rate rate 

​

let (crate, lrate) = convert_func(10.0)

​

crate |> printfn "%A"

lrate |> printfn "%A"

​

​