Question

how to compute a gpa?
and is this correct??
cout<<"PRELIM";
cout<<"/n/n";
cout<<"Laboratory:";
cin>>dbllab;
cout<<"Exam:";
cin>>dblex;
cout<<"Project:";
cin>>dblpro;
dblpg=(dbllab * .6) + (dblex * .2) + (dblpro * .2);
cout<<"Prelim Grade:"<<dblpre<<endl;