It might help to get a sample in jsFiddle, but it looks like:
For this one: <ul data-bind="sortable: {foreach:Questions}">
You want either just sortable: Questions
which is equivalent to sortable { data: questions }
For this one: <ul data-bind="sortable: { template: 'questions', foreach:Questions}" width="80%"></ul>
You want: sortable: { template: 'questions', data: Questions }
So, mainly just using data
instead of foreach