Elliott has some yard that she wants to use to make hats and scarves each hat uses .2 kg of yarn and each scarf uses .1 kilograms of yarn. Elliott wants to use twice as much yarn for scarves as for hats, and she wants to make a total of 20 items. Let h be the number of hats Elliot makes and s be the number of hats Elliot makes and a be the number of scarves she makes. Which system represents this situation?