open System
let xs = [1; 2; 3; 4; 5]
let results = xs |> List.filter(fun x -> x % 2 = 0) |> List.map(fun x -> 10 * x)
printfn "%A" results
b3BlbiBTeXN0ZW0KCmxldCB4cyA9IFsxOyAyOyAzOyA0OyA1XQoKbGV0IHJlc3VsdHMgPSB4cyB8PiBMaXN0LmZpbHRlcihmdW4geCAtPiB4ICUgMiA9IDApIHw+IExpc3QubWFwKGZ1biB4IC0+IDEwICogeCkKCnByaW50Zm4gIiVBIiByZXN1bHRz