yakubun-easy.js

var p = console.log.bind(console);
var q = require('readline-sync').question;
var gcd = (a, b) => !b ? a : gcd(b, a % b);
var r = () => Math.floor(Math.random()*9)+1
var i = 1;
for(;;) {
	var x = r();
	var y = r();
	var df = x % y === 0;
	if(df) continue;
	var g = gcd(x, y);
	if(g === 1) continue;
	var sn = x/g;
	var sd = y/g;
	p(`(${i}) ${x}/${y}`);
	var a = q('Input the answer: ');
	var as = a.split('/');
	var an = parseInt(as[0]);
	var ad = parseInt(as[1]);
	var c = an === sn && ad === sd;
	p(c ? 'Good!' : `Bad: The correct answer is ${sn}/${sd}`);
	i++;
}

yakubun.js

var p = console.log.bind(console);
var q = require('readline-sync').question;
var gcd = (a, b) => !b ? a : gcd(b, a % b);
var r = () => Math.floor(Math.random()*9)+1
var i = 1;
for(;;) {
	var x = r();
	var y = r();
	var z = r();
	var xz = x * z;
	var yz = y * z;
	var df = x % y === 0;
	if(df) continue;
	var g = gcd(x, y);
	if(g === 1) continue;
	var sn = x/g;
	var sd = y/g;
	p(`(${i}) ${xz}/${yz}`);
	var a = q('Input the answer: ');
	var as = a.split('/');
	var an = parseInt(as[0]);
	var ad = parseInt(as[1]);
	var c = an === sn && ad === sd;
	p(c ? 'Good!' : `Bad: The correct answer is ${sn}/${sd}`);
	i++;
}