The appropriate conversion factor here is
545 grams
-------------- = 1
1 lb
Let's change over to kg:
545 grams 1 kg
-------------- * ---------- = 0.545 kg/lb. We were asked "how many pounds are
1 lb 1000 g there per lb? To obtain this, invert
0.545 kg/lb:
1 lb
----------------- = 1.83 lb/kg
0.545 kg/lb