window.onload = function() { /* Elements of DOM */ var body = document.getElementsByTagName("body")[0]; var wrap = document.getElementById("wrap"); var timer = document.getElementById("timer"); var question = document.getElementById("question"); var answers = document.getElementById("answers"); var textarea = document.getElementsByTagName("textarea")[0]; var button = document.getElementById("start_button"); var result = document.getElementById("result"); var q_number = 1; /* Screen parameters */ var width = document.documentElement.clientWidth; var height = document.documentElement.clientHeight; body.style.width = width-4+"px"; body.style.height = height-4+"px"; wrap.style.width = width-4+"px"; wrap.style.height = height-4+"px"; /* Button functionality */ var flag = true; var num_cor_ans = 0; var check; var disable_btn = false; button.onclick = function() { if (flag) { // If we just start the challenge Next_Question(); } else if (textarea.value != "") { clearTimeout(check); // If we check our answer timer.classList.toggle("timer"); if ((textarea.value.toLowerCase() == Answers[q_number-1]) && !(disable_btn)){ // If the answer is right disable_btn = true; num_cor_ans +=1; result.innerHTML = `Correct
+${num_cor_ans}`; result.classList.toggle("correct"); setTimeout(function () {question.classList.add("question_out"); textarea.value = "";}, 1500); setTimeout(function () {question.classList.remove("question_out")}, 2500); setTimeout(Next_Question, 2500); } if ((textarea.value.toLowerCase() != Answers[q_number-1]) && !(disable_btn)){ // If the answer is wrong disable_btn = true; result.innerHTML = "Wrong"; result.classList.toggle ("wrong"); setTimeout(function () {question.classList.add("question_out"); textarea.value = "";}, 1500); setTimeout(function () {question.classList.remove("question_out")}, 2500); setTimeout(Next_Question, 2500); } } } /* Choose a question */ function Next_Question() { disable_btn = false; if (q_number > 5) { result.classList.remove("correct"); result.classList.remove("wrong"); question.classList.remove("question_in"); result.innerHTML = `Your result:
${num_cor_ans} out of 5`; result.style.color = "blue"; button.innerHTML = "TRY AGAIN"; textarea.style.display = "none"; flag = true; q_number = 1; num_cor_ans = 0; } else { button.innerHTML = "CHECK"; flag = false; setTimeout(function() { timer.classList.toggle("timer"); check = setTimeout(Check_if_clicked,45000)},1200); result.innerHTML = ""; question.innerHTML = Questions[q_number]; q_number += 1; question.classList.add("question_in"); textarea.value = ""; textarea.style.display = "block"; result.classList.remove("correct"); result.classList.remove("wrong"); } } /* If run out of time */ function Check_if_clicked () { timer.classList.toggle("timer"); result.innerHTML = "Time is out"; result.classList.toggle ("wrong"); setTimeout(function () {question.classList.add("question_out"); textarea.value = "";}, 1500); setTimeout(function () {question.classList.remove("question_out")}, 2500); setTimeout(Next_Question, 2500); } /* Questions and Answers */ var Questions = { 1: "What is the result:

(35-17)*13+(57-34)*11 = ?", 2: "What is the result:

23*21-134+43*7-123 = ?", 3: "What is the result:

2*3*4*5*6*7-123 = ?", 4: "What is the result:

3+14+25+32+41+56+68 = ?", 5: "What is the result:

761-62-54-45-37-23-18-9 = ?" } var Answers = { 1: eval((35-17)*13+(57-34)*11), 2: eval(23*21-134+43*7-123), 3: eval(2*3*4*5*6*7-123), 4: eval(3+14+25+32+41+56+68), 5: eval(761-62-54-45-37-23-18-9) } }

✅Math Test👨‍🎓Try to solve in 45 sec😅