Ladder #228 is five finishes in a row: 4, 56, 62, 82 and 113. You get one turn of three darts for each, and every finish has to end on a double or the bull.
4 is a straight double: D2. If the dart lands in the single by mistake you are left on 2, which still has a double finish with the darts you have left. 56 is a two-dart finish: 16 D20.
62 is a two-dart finish: T18 D4. 82 is a two-dart finish: T14 D20. 113 needs all three darts: T18 19 D20. If the first dart misses its treble, the board will show the new route straight away.
At best the five finishes need 10 darts out of 15. Your result counts the finishes you make first and the darts you used second. The middle finishes decide this ladder. Choose the route that leaves a double after a missed treble; the suggested routes do that wherever they can.