[ [ RowDataPacket { id: 1, text: 'один-два дня', id_question: 1, answer: 1 },
    RowDataPacket { id: 2, text: 'более 5 дней', id_question: 1, answer: 0 },
    RowDataPacket { id: 3, text: '3-5 дней', id_question: 1, answer: 0 } ],
  [ RowDataPacket { id: 4, text: 'да', id_question: 2, answer: 1 },
    RowDataPacket { id: 5, text: 'нет', id_question: 2, answer: 0 },
    RowDataPacket {
      id: 6,
      text: 'не постоянно, Меняется постоянно',
      id_question: 2,
      answer: 0 } ],
  [ RowDataPacket { id: 7, text: 'да', id_question: 4, answer: 0 },
    RowDataPacket { id: 8, text: 'нет', id_question: 4, answer: 0 },
    RowDataPacket { id: 9, text: 'не помню', id_question: 4, answer: 1 } ] ]

for(i=0; i < answearArr.length; i++){
            let arr = answearArr[i];
            console.log(arr.find({answer: 0}))
        }

TypeError: # is not a function

console.log(arr.find(function(item){ return item.answer == 1; }));

console.log(questions.map(function(question){ return question.find(
  function(answer){ return answer.answer == 1; }
)}));