Question du test Javascript

Que renverra l'expression suivante ?

[
    { name:'Lisa'    , mark:'16' },
    { name:'Pascal'  , mark:'13' },
    { name:'Romain'  , mark:'12' },
    { name:'Lucas'   , mark:'4'  },
    { name:'Aurélie' , mark:'14' }
]
.map(function(student) { student.mark = Number(student.mark); return student })
.filter(function(student) { return student.mark >= 10 })
.reduce(function(acc, student) { return student.mark + acc }, 0);