Yes, here is the full controller: 

public class OpportunityExt {

    private final Opportunity opp;
    
    public OpportunityExt(ApexPages.StandardController stdController) {
        this.opp = (opportunity)stdController.getRecord();
    }
    

    public integer getOpenTasks() {
        return [SELECT count() FROM task WHERE whatid = :opp.id and IsClosed=false];
    } 

   
    public decimal getFunnel() {
        AggregateResult ar = [SELECT Sum(Lic_Revenue__c)s FROM opportunity WHERE ownerid = :opp.ownerid and Close_FQ__c = :opp.Close_FQ__c and Probability != 0];
        decimal RepFun; 
        	if ( ar.get('s') == null) {RepFun = 0;} else {RepFun = (decimal)ar.get('s');}
        	
        decimal d1;
        	if(opp.Lic_Revenue__c != null && RepFun != 0){d1 = (opp.Lic_Revenue__c / RepFun) * 100;} else {d1 = 0;}
        
        return d1.setScale(1);
    }
    
    public decimal getProposalScore() {
        AggregateResult ar2 = [SELECT AVG(total_score__c)a FROM Proposal__c WHERE Opportunity__c = :opp.id];
        decimal p1 = (decimal)ar2.get('a');
        return p1;
    }
     
    public integer getAge() {
    	date close;
    		if( opp.CloseDate == null) {close = system.today();} else {close = opp.CloseDate;}
    	date cdate = date.valueof(opp.CreatedDate);
    	integer openAge = cdate.daysbetween(system.today());
    	integer closeAge = cdate.daysBetween(close);
        if(opp.isClosed == true && closeAge != null && openAge != null) { return closeAge + 1; } else {return openAge + 1;} 
    }   
    

and here is the testclass

public class OpportunityExt_TestClass {
static testMethod void OpportunityExt()
{
//Test converage for the myPage visualforce page
PageReference pageRef = Page.OpportunityQuickView;
Test.setCurrentPageReference(pageRef);

//Create Account
Account ac = new Account (name='XYZ Organization');
insert ac;


//Create Opportunity
Opportunity op = new Opportunity (name='test opportunity');
op.Account = ac;
op.Type = 'New Users';
op.Lic_Revenue__c = 5; 
op.StageName = 'Win'; 
op.Push_Count_FQ__c = 2; 
op.CloseDate = system.today()+365;
insert op;

//Create Opportunity
Opportunity op2 = new Opportunity (name='test opportunity');
op2.Account = ac;
op2.Type = 'New Users';
op2.Lic_Revenue__c = null; 
op2.StageName = 'Win'; 
op2.Push_Count_FQ__c = 2; 
op2.CloseDate = system.today()+365;
insert op2;

ApexPages.StandardController sc = new ApexPages.standardController(op);
// create an instance of the controller
OpportunityExt myPageOpp = new OpportunityExt(sc);

//try calling methods/properties of the controller in all possible scenarios
// to get the best coverage.
integer OpenTasks = myPageOpp.getOpenTasks();
decimal Funnel = myPageOpp.getFunnel();
decimal ProposalScore = myPageOpp.getProposalScore();
string ShortID = myPageOpp.getShortID();
decimal AgeProb = myPageOpp.getAgeProb();
integer age = myPageOpp.getAge();


ApexPages.StandardController sc2 = new ApexPages.standardController(op2);
// create an instance of the controller
OpportunityExt myPageOpp2 = new OpportunityExt(sc2);

//try calling methods/properties of the controller in all possible scenarios
// to get the best coverage.
integer OpenTasks2 = myPageOpp2.getOpenTasks();
decimal Funnel2 = myPageOpp2.getFunnel();
decimal ProposalScore2 = myPageOpp2.getProposalScore();
string ShortID2 = myPageOpp2.getShortID();
decimal AgeProb2 = myPageOpp2.getAgeProb();
integer age2 = myPageOpp.getAge();
}
}