03. Time + 15 Minutes

function timePlus15(input) {
    let inputHours = Number(input[0]);
    let inputMinutes = Number(input[1]);
    let totalMinutes = inputHours * 60 + inputMinutes + 15;
    let hours = Math.floor(totalMinutes / 60) % 24;
    //let hours = parseInt(totalMinutes / 60) % 24;
    let minutes = totalMinutes % 60;

    // a) РЕШЕНИЕ С IF-ELSE:
    if (minutes < 10) {
        console.log(`${hours}:0${minutes}`);
    } else {
        console.log(`${hours}:${minutes}`);
    }

    //b) РЕШЕНИЕ С ТЕРНАРЕН ОПЕРАТОР:
    console.log(`${hours}:${minutes % 60 < 10? '0' : ''}${minutes}`);

    //c) РЕШЕНИЕ С МЕТОДИТЕ toString() и padStart():
    console.log(`${hours}:${minutes.toString().padStart(2, '0')}`);
}

ИЛИ ЛЕКО ТАРИКАТСКАТА:)

function timePlus15(input) {
    let totalMinutes = Number(input[0]) * 60 + Number(input[1]) + 15;

    console.log(`${parseInt(totalMinutes / 60) % 24}:${(totalMinutes % 60).toString().padStart(2, '0')}`);
}