between query on mongodb

i have this collection

{ "_id" : ObjectId("57b8277cd48b97d6e38d9eb2"),

"student_id" : "326598",
"sem" : "sem1",
"marks" : [ 
    {
        "title" : "english",
        "from" : 2,
        "to" : 15
    }, 
    {
        "title" : "maths",
        "from" : 5,
        "to" : 18
    }, 
    {
        "title" : "science",
        "from" : 10,
        "to" : 20
    }
]

}

{ "_id" : ObjectId("52873b7e4038253faa4bbc10"),

"student_id" : "124578",
"sem" : "sem1",
"marks" : [ 
    {
        "title" : "english",
        "from" : 1,
        "to" : 20
    }, 
    {
        "title" : "maths",
        "from" : 6,
        "to" : 16
    }, 
    {
        "title" : "science",
        "from" : 12,
        "to" : 20
    }
]

}

and write this query :

var x= 7;
db.getCollection('numbers').aggregate([
{$unwind : "$marks"},
{$match : {$and :[{"marks.from": { $gte :2 } },{"marks.to": { $lte :15 } } ]}}
])

i want return each document contains X value is in range between from and to . for example return document that have X value great than marks.from and less than marsk.to . but that query didnt work.