8.js

function solve(month, overNightNumber) {
    overNightNumber = Number(overNightNumber);

    let studioPricePerNight;
    let apratmentPricePerNight;
    let studioPrice;
    let apartmentPrice;

    if (month === 'May' || month === 'October') {
        studioPricePerNight = 50;
        apratmentPricePerNight = 65;

        studioPrice =  overNightNumber * studioPricePerNight;
        apartmentPrice = overNightNumber * apratmentPricePerNight;

        if (overNightNumber >= 7) {
           studioPrice = studioPrice - studioPrice * 0.05;
        } else if (overNightNumber >= 14) {
            studioPrice = studioPrice - studioPrice * 0.3;
        }

    } else if (month === 'June' || month === 'September') {
        studioPricePerNight = 75.20
        apratmentPricePerNight = 68.70

        studioPrice = overNightNumber * studioPricePerNight;
        apartmentPrice = overNightNumber * apratmentPricePerNight;

        if (overNightNumber >= 14) {
            studioPrice = studioPrice - studioPrice * 0.2;
        }

    } else if (month === 'July' || month === 'August') {
        studioPricePerNight = 76;
        apratmentPricePerNight = 77;

        studioPrice = overNightNumber * studioPricePerNight;
        apartmentPrice = overNightNumber * apratmentPricePerNight;
    }

    if (overNightNumber >= 14) {
        apartmentPrice = apartmentPrice - apartmentPrice * 0.1;
    }

    console.log(`Apartment: ${apartmentPrice.toFixed(2)} lv.`);
    console.log(`Studio: ${studioPrice.toFixed(2)} lv.`);
}