// students score, total possible score
// 15/20 -> You got a C (75%)!
// A 90-100, B 80-89, C 70-79, D 60-69, F 0-59

let gradeCalc = function (score, totalScore) {
    let percent = (score / totalScore) * 100
    let letterGrade = ' '

    if (percent >= 90) {
            letterGrade = 'A'
    } else if (percent >= 80) {
        letterGrade = 'B'
    } else if (percent >= 70) {
        letterGrade = 'C'
    } else if (percent >= 60) {
        letterGrade = 'D'
    } else {
            letterGrade = 'F'
    }

    return `You got a ${letterGrade} (${percent}%)!`
}

let result = gradeCalc(15, 20)
console.log(result)