TAMPA, Fla. (MCT) — Mixing earnestness with youthful gumption, Rep. Paul Ryan introduced himself to the nation with a pledge Wednesday night to join Mitt Romney in tackling the country’s most intractable problems while setting the economy on a path to create 12 million jobs over the next four years.

“Before the math and the momentum overwhelm us all, we are going to solve this nation’s economic problems. We don’t have that much time,” Ryan said in a prime-time speech that was rousingly received at the Republican National Convention. “But if we are serious and smart and we lead, we can do this.”