JQ filter problem

examples.json

# Create jq filter for JSON below that prints "foobar" by testing for which object has Key == "Name" in Tags array.
# However, if the object where Key == "Name" is removed the answer should be null and only one null

{
    "Tags": [
        {
            "Value": "CORE",
            "Key": "aws:elasticmapreduce:instance-group-role"
        },
        {
            "Value": "j-2PX6VIU90YUXV",
            "Key": "aws:elasticmapreduce:job-flow-id"
        },
        {   
            "Value": "foobar",
            "Key": "Name"
        }
    ]
}

# json below should print a single null as there is no object where Key == "Name"
{
    "Tags": [
        {
            "Value": "CORE",
            "Key": "aws:elasticmapreduce:instance-group-role"
        },
        {
            "Value": "j-2PX6VIU90YUXV",
            "Key": "aws:elasticmapreduce:job-flow-id"
        }
    ]
}