Algoritms tasks

It's New Year's Eve soon, so Ivan decided it's high time he started setting the table. Ivan has bought two cakes and cut them into pieces: the first cake has been cut into a pieces, and the second one — into b pieces.
Ivan knows that there will be n people at the celebration (including himself), so Ivan has set n plates for the cakes. Now he is thinking about how to distribute the cakes between the plates. Ivan wants to do it in such a way that all following conditions are met:

To make his guests happy, Ivan wants to distribute the cakes in such a way that the minimum number of pieces on the plate is maximized. Formally, Ivan wants to know the maximum possible number x such that he can distribute the cakes according to the aforementioned conditions, and each plate will contain at least x pieces of cake.
Help Ivan to calculate this number x!

            window.onload = function() {
                var outputAnswer = document.querySelector('.answer span'),
                    inputData = document.querySelector('input[data-function="data"]'),
                    data,
                    plates,
                    piecesFirstCake,
                    piecesSecondCake,
                    result = 0;
                    
                inputData.onchange = function() {       
                    data = document.querySelector('input[data-function="data"]').value.split(' ');
                    plates = +data[0];
                    piecesFirstCake = +data[1];
                    piecesSecondCake = +data[2];
                    findMinimumPiecesInPlate(plates, piecesFirstCake, piecesSecondCake);
                };
            
                function findMinimumPiecesInPlate(plates, piecesFirstCake, piecesSecondCake) {        
            
                    if (checkConditions(plates, piecesFirstCake, piecesSecondCake)) {
                        outputAnswer.innerHTML = result;
                        return;
                    }        
            
                    result = 1;
                    var divideFirst = 0,
                        divideSecond = 0;
                    for (var i = 2; i < plates; i++) {
                        if (piecesFirstCake > piecesSecondCake) {
                            piecesFirstCake /= 2;
                            var k = 0;
                            if (divideFirst) k = 2;
                            for (var j = 1; j <= divideFirst; j++) {
                                k *= j;
                            }
                            i += k;
                            divideFirst++;  
                        } else {
                            piecesSecondCake /= 2;
                            var k = 0;
                            if (divideSecond) k = 2;
                            for (var j = 1; j <= divideSecond; j++) {
                                k *= j;
                            }
                            i += k;
                            divideSecond++;  
                        }
                    }
                    
                    result = Math.min(Math.floor(piecesFirstCake), Math.floor(piecesSecondCake)) || 1;
                    outputAnswer.innerHTML = result;
                }
            
                function checkConditions(plates, piecesFirstCake, piecesSecondCake) {
                    if (plates < 2) {
                        result = 'Incorrect number of plates. Please change it.';
                        return true;
                    }
            
                    if (piecesFirstCake < 1) {
                        result = 'Incorrect pieces of first cake. Please change it.';
                        return true;
                    }
            
                    if (piecesSecondCake < 1) {
                        result = 'Incorrect pieces of second cake. Please change it.';
                        return true;
                    }
            
                    return false;
                }
            };

Task 3