MongoDB remove object from array deletes complete array -

i have document one:

{         "_id" : 0,         "name" : "aimee zank",         "scores" : [                 {                         "type" : "exam",                         "score" : 1.463179736705023                 },                 {                         "type" : "quiz",                         "score" : 11.78273309957772                 },                 {                         "type" : "homework",                         "score" : 6.676176060654615                 },                 {                         "type" : "homework",                         "score" : 35.8740349954354                 }         ] } 

on document want delete score has lowest score of type homework. first, i'm trying on mongo shell, put values manually.

 db.students.update({ _id:0}, {$unset: {"scores.score":6.676176060654615} }) 

that query nothing, tried search on google , found here question removing object array , tried other query:

db.students.update({ _id:0 }, { $unset:                                     { "scores": {                                          "homework": 6.676176060654615 } } }, false, true); 

the second query worked, not expected because result was

{ "_id" : 0, "name" : "aimee zank" } 

to check lowest value of type homework exists find query:

db.students.find({"scores.score":6.676176060654615}).pretty(); 

if want delete/pull score = 6.676176060654615, need use following query :

db.collection.update({"_id":0},{"$pull":{"scores":{score: 6.676176060654615}}}) 

if want find minimum value , remove collection. need 2 steps. more details refer this