[CiliZ]

for (var i = 0; i < 15; i++) {
    var element = document.getElementById('otvet' + (i + 1)), chAtEq = answ.charAt([i]) == "1";
    element.style.backgroundColor = chAtEq ? "#afa" : "#faa";
    element.innerHTML = chAtEq ? "Верно" : "Не верно";
}