creating a small maths game need help

hi guys!!
i am wrting a program for a small arithemtic game,it displays two numbers and ask user to enter the sum of these two numbers,the program runs fine but i want to add a countdown timer,i mean time limit for user to answer all 10 questions within 30 seconds.i hav tried everything but dint came up with any idea
it should display the timer and questions.plzz help i am new to programming

here is the code

void addtion()
{
     int firstran,secondran,num1,num2,sum,in1,ans,count=0,right=0,worng=0,score=0;
     cout<<"\t\t\t\tADDTION\n";
                               for(int k=0;k<80;k++)
                              {
                                  cout<<"-";
                                  delay1();
                              }
                              cout<<"\n\nREADY????";
                              delay1();
                              cout<<"\n\nENTER A CHAR WHEN READY.....\n";
                              cin>>in1;
                              system("cls");
                              cout<<"\t\t\t\tLEVEL 1\n";
                              ////print lines----------------------------------
                              for(int i=0;i<80;i++)
                              {
                                  cout<<"-";
                                  delay1();  //delay to print cgar by char
                              }
                              cout<<"\t\t\t\tADDTION\n";
                               for(int k=0;k<80;k++)
                              {
                                  cout<<"-";
                                  delay1();
                              }
                              //////////--------------------------------------
                              cout<<"\nGO!!\n";
                              for(int i=10;i>0;i--)                                                                                                               
                              {
                                      
                                      firstran=random();                                                                                        
                              num1=gennumber(firstran);                          ///generate two random numbers for addtion//////
                              secondran=random2(num1);                           //gennumer generates number within 99 for level 1///
                              num2=gennumber(secondran);
                              count++;
                              sum=num1+num2;
                            cout<<count<<"  ->  "<<num1<<"  +  "<<num2<<"  = ";
                              cin>>ans;
                              
                              if(ans==sum)
                              {
                                    right++;
                                    score=score+10;
                              }
                              else { worng++;}                              
                              }
                              
                              
                              results(right,worng,score);                 ////prints the result to std output///
                              getinfo(score);                             ///get player name and store it in file with scores////
                              viewscores();                               ///read names from the file and display it on std output///
                                      
                              
                              
}