В MySQL это будет работать:
SELECT count(Answers.ID) as answertotal, Questions.*
FROM Questions
LEFT JOIN Answers ON Answers.qid=Questions.ID
GROUP BY Questions.ID
ORDER BY answertotal
В SQLLite вам может понадобиться добавить дополнительный слой, подобный этому:
SELECT q.*, tots.answertotal
FROM Questions q
INNER JOIN (
SELECT count(Answers.ID) as answertotal, Questions.ID as questionid
FROM Questions
LEFT JOIN Answers ON Answers.qid=Questions.ID
GROUP BY Questions.ID
) tots ON tots.questionid = q.ID
ORDER BY tots.answertotal